Causes of Numbness and Tingling (Paresthesia) in Fingertips

What Does Numbness and Tingling Mean?

• Numbness means decreased or absent sensation in the skin; the medical terms are hypoesthesia and anesthesia.
• Tingling means weird feeling often described as “pins and needles” or “ants crawling;” the medical term is paraesthesia.

Some people use the terms numbness and tingling interchangeably.

Numbness and Tingling

Quick Symptom Checker

One or more fingertips have SUDDENLY become WHITE, BLUE or BLACK, painful, cool and numb and this is not due to cold temperatures. This may be arterial embolism or severe arterial spasm. Do not search further and visit a doctor immediately, otherwise you risk losing your finger.

Tingling in hands and PROGRESSING DIZZINESS can be from hypoglycemia (mainly in diabetics), other metabolic disorder or hyperventilation.

NUMBNESS followed by WEAKNESS, QUICKLY PROGRESSING (hours, days) from the toes to legs or from the fingertips to arms can be due to Guillain-Barre syndrome or a metabolic disorder. Visit a doctor as soon as possible.

SUDDEN NUMBNESS ON ONE SIDE OF THE BODY can be from stroke. Numbness in the left or right arm associated with CHEST PAIN can be from heart disease (angina pectoris, heart attack).

One or more fingertips has QUICKLY become RED, very painful and numb. This can be a bacterial infection of the fingertip (felon). Visit a doctor.

After brief exposure to cold, some of your fingertips turn WHITE and numb, then BLUE, then RED and may be or not painful. This is likely Raynaud’s phenomenon.

Your fingers are OFTEN or CONSTANTLY BLUISH and numb. Search for causes of cyanosis.

You have recurring or persistent numbness in one or more of the FIRST THREE FINGERS. This is likely carpal tunnel syndrome.

You have recurring or persistent numbness in the PINKY finger. This is likely cubital tunnel syndrome or Guyon’s canal syndrome.

Innervation of the Fingertips

• Tips of the first three fingers (the thumb, index and middle) and the adjacent half of the ring finger are innervated by the median nerve.
• The pinky finger and the adjacent half of the ring finger are innervated by the ulnar nerve.

Picture 1. Innervation of the fingers
Green: The median nerve
Blue: The ulnar nerve
Red: The radial nerve
(source: Commons.wikimedia.org)

The Blood Supply of the Fingers

The fingers get blood via the digital arteries, which are branches of the radial and ulnar artery, which extends from the brachial artery, this from the axillary artery and this from the subclavian artery, which arises from the aorta. Digital arteries and nerves run on the both sides of the fingers.

Causes

You can check for categories (A-F) of causes of numbness in the fingertips in the Table of Contents on the top of the article.

A. FOODS, ALLERGENS, DRUGS, TOXINS

Numbness in the fingertips after eating is not common. The main skin symptom in food allergies is usually itchiness and rash, not numbness.

Coffee and Other Caffeinated Beverages

Caffeine in doses greater than 600-1,000 milligrams (6-10 cups of coffee or 12-20 cups of tea) per day may result in chronic caffeine intoxication or caffeinism with anxiety, insomnia, tingling in the fingertips and around the mouth; tingling is caused by hypocalcemia and this by hyperventilation due to anxiety ^{(155,156,278)}.

Smoking

• Nicotine (smoking) constricts the blood vessels ⁽¹⁴¹⁾. Smoking can increase the risk of arterial spasms in the fingers (Raynaud’s phenomenon) in men ⁽¹³⁸⁾.
• Heavy smoking (or tobacco chewing) can cause Buerger’s disease.

Alcohol

• In women, heavy drinking increases the risk of Raynaud’s phenomenon ⁽¹³⁸⁾.
• Heavy drinkers can develop alcoholic neuropathy with numbness and tingling, which can, in few months, progress from the toes to the knees and later from the fingertips to the wrists (dying back neuropathy) resulting in a “stockings and gloves” pattern ^(63,279). Alcoholic neuropathy may be reversible; after stopping drinking and with proper nutrition, symptoms may gradually disappear ⁽²⁸⁰⁾.
• The mushrooms inky caps (Coprinus atramentarius), when eaten along with alcohol, can cause disulfiram-like reaction with facial flushing and numbness in the limbs ⁽³⁰⁴⁾.

Seafood Poisoning

• Eating the poisonous sea snails red whelks, which contain tetramine in their salivary glands, can cause tingling in the fingers, double vision and diarrhea ^{(173,174,175)}.
• Ciguatera and neurotoxic shellfish poisoning ^(171,172). Ciguatoxin from large tropical fish (e.g. barracuda, grouper, moray eel, amberjack, sea bass, or sturgeon) and brevetoxin from shellfish can cause reversal of hot and cold sensation (allodynia): for example, when an affected person touches cold water, it feels hot. Other symptoms: itching, numbness around the mouth, in hands and feet, diarrhea. Symptoms may persist for several days, weeks or months.
• Fish tapeworm (Diphyllobothrium latum) infestation caused by by eating fish may cause numbness in various parts of the body ⁽³⁴⁴⁾.
• Toxins in buffalo fish or salmon can cause Haff disease with numbness in the limbs ^(82,344).

Drugs and Supplements

A list (not complete) of drugs that can cause numbness or tingling in the fingertips:

• Anesthetics
  • Intramuscular injections of local anesthetics: lidocaine (in the finger surgery)
  • Applying anesthetic creams, ointments, gels containing benzocaine, capsaicin, lidocaine, ketamine, pramoxine or tetracaine
• Antibiotics: nitrofurantoin, norfloxacin ⁽²⁹⁸⁾
• Antidepressants: phenelzine, tranylcypromine sulfate, trazodone ⁽²⁹⁸⁾
• Acyclovir (an antiviral drug) ⁽³⁷⁴⁾
• Apraclonidine ⁽²⁹⁸⁾
• Arginine supplements ⁽²⁹⁸⁾
• Beta-alanine supplements in doses greater than 800 mg ⁽³³³⁾
• Bromocriptine ⁽¹⁵⁴⁾
• Carbidopa, levodopa ⁽²⁹⁸⁾ selegiline ⁽³¹⁰⁾ (for Parkinson’s disease)
• Chemotherapy: carboplatin, cisplatin, docetaxel, everolimus ⁽²⁹⁵⁾, paclitaxel, vincristine ⁽²⁹⁴⁾.One side effect of certain chemotherapeutics is hand-foot syndrome (“acral erythema” or “palmar-plantar erythrodysesthesia”) with numbness, tingling, pain, redness, swelling or flaking of the palms, fingers, soles and toes.
• Clopidogrel ⁽²⁹⁸⁾
• Dextromethorphan (DXM) ⁽³⁰¹⁾
• Diuretics (acetazolamide, metolazone) ⁽²⁹⁸⁾
• Ergotamine ⁽¹⁵³⁾ ,methysergide ⁽¹⁵⁴⁾, topiramate ⁽³³³⁾ (for migraine)
• Ergonovine, methylergometrine (to stop bleeding after delivery) ⁽¹⁵⁴⁾
• Ethambutol and isoniazid (for tuberculosis) ⁽²⁹⁰⁾
• Germanium supplements ⁽⁵⁴⁾
• Immunosuppressants: cyclosporine ⁽²⁹⁷⁾, mycophenolate ⁽²⁹⁸⁾
• Permethrin (for scabies) ⁽²⁹⁸⁾
• Selenocysteine supplements ^(92,794)
• Statins: atorvastatin ⁽³²⁶⁾
• Zoledronic acid ⁽²⁹⁶⁾ (for osteoporosis)
• Drugs that can trigger hyperventilation
• Drugs that can trigger Raynaud’s phenomenon
• Drugs that cause peripheral neuropathy
• Drugs that can cause hypocalcemia
• Drugs that can cause carpal tunnel syndrome

Illegal Drugs

Stimulant drugs that can cause numbness triggered by hyperventilation:

• Cocaine, crack overdose ⁽³¹²⁾
• Amphetamine ⁽³¹³⁾
• Ecstasy (MDMA) ⁽³⁰¹⁾

Hallucinogens:

• Glue sniffing (n-hexane in glue causes peripheral neuropathy) ⁽¹⁴⁴⁾
• Ketamine ⁽³⁰²⁾
• Nitrous oxide (laughing gas) inhalation (by using “whippets”) can cause peripheral neuropathy ^(333,343)
• Phencyclidine (angel dust) ⁽³⁴⁴⁾

Poisons, Toxins, Pesticides

• Methanol or ethylene glycol ingestion ⁽³³⁷⁾
• Pyrethrin (aircraft disinfectant) ⁽²⁹⁹⁾
• Organophosphates (pesticides) inhalation–exposure lasting 1-4 weeks can cause neuropathy ⁽³⁴⁰⁾
• Warfare nerve gases (sarin, soman, tabun) ⁽³⁴¹⁾
• Strychnine (contact) ⁽³¹⁹⁾
• Cone snail (cone shell) sting can cause localized burning pain, numbness and tingling,which may spread to the entire limb ⁽¹⁷⁶⁾. Numbness may persist for weeks ^(177,p.25).
• Drinking sea water contaminated with harmful cyanobacterial blooms (HCB) may cause diarrhea and numbness and tingling in fingers and toes ⁽¹⁷⁹⁾.
• Poisoning with elemental (metal) mercury in children: pink, numb or painful fingers, peeling hands and leg cramps (acrodynia, pink disease) ^(344,363)
• Lead poisoning ⁽³⁴⁴⁾.

Stinging Nettle

Contact with the stinging nettle leaves or stems can result in burning and itchy red patches (contact urticaria), followed by numbness and tingling that may persist from 30 minutes to more than 12 hours ^(83,84).

Insect Bites and Stings, Snake Bites

• Stings of venomous insects, such as a bee, wasp, hornet, spider (black widow, brown recluse spider) and scorpion, can cause burning pain, redness, blisters and swelling in the affected fingertip, followed by tingling and numbness, which may persist for a day or two ^(78,79,87).
• Bites of non-venomous insects, such as mosquito, horse fly, flea, scabies mites, bed bugs, lice, ticks, chiggers and cockroaches, can cause itchy red bumps, sometimes followed by tingling and numbness ^(80,88). NOTE: The exact site of the insect bite may not be always seen.
• Bites of poisonous snakes, such as cobra or rattlesnake, to the arm can cause numbness and tingling in the affected area spreading toward the fingertips ^(81,344).

B. METABOLIC DISORDERS

Hyperventilation, hypocalcemia, hypokalemia, hyperkalemia, hypomagnesemia, hypophosphatemia and hypoglycemia can cause numbness and tingling in the fingertips.

Hyperventilation and Respiratory Alkalosis

Symptoms of hyperventilation may begin within three minutes of onset and may include numbness and tingling in the fingertips, hands and around the mouth, muscle cramps, chest tightness and dizziness ^(1,19,334).

Mechanism. Hyperventilation can result in respiratory alkalosis, which leads to hypocalcemia and hypokalemia, which can result in narrowing of the arteries and decreased blood flow in the fingers ^(19,20).

Causes of hyperventilation ^{(19,20,40,283)}:

• Long-distance running (marathon, triathlon), cycling or other prolonged heavy exercise
• High altitude
• Pregnancy
• Sleep apnea
• Severe pain
• Fever, heat exhaustion
• Anxiety, panic attack, hysteria, psychosis can be associated with hyperventilation syndrome ⁽¹⁾
• Low blood pressure (hypotension) due to severe bleeding, severe dehydration (more than 5% water loss) ⁽³³³⁾, sepsis, shock, dysautonomia (vasovagal syncope, orthostatic hypotension) ⁽³⁴⁴⁾
• Kidney failure
• Pneumonia, pulmonary edema, pneumothorax, pulmonary embolism, interstitial lung disease, aspiration, asthma, emphysema, chronic bronchitis, acute respiratory distress syndrome (ARDS)
• Infectious diseases, such as meningitis or encephalitis
• Alcohol withdrawal
• Diabetic ketoacidosis
• Hyperthyroidism
• Liver failure, cirrhosis
• Congestive heart failure, cardiogenic shock
• Severe anemia ⁽⁴⁰⁾
• Head injury, stroke, brain tumor
• Drugs: salicylate (aspirin) toxicity, methylxanthine toxicity, epinephrine, amphetamines, progesterone, nicotine, bronchodilators (epinephrine, isoproterenol, salmeterol, terbutaline, theophylline) ^(307,347), doxapram ⁽³¹⁴⁾, atomoxetine ⁽³⁰⁵⁾, armodafinil ⁽³⁰⁶⁾, ephedrine (nasal decongestant) ⁽³⁰⁷⁾, methylphenidate ⁽³⁰⁸⁾, modafinil ⁽³⁰⁹⁾, phentermine and sibutramine (appetite suppressants) ^(300,311).
• Mechanical ventilation
• Metabolic acidosis due to ^{(336,337,349)}:
  • Severe diarrhea or dehydration
  • Kidney disease
  • Poisoning with aspirin, methanol, ethylene glycol, iron, ammonium chloride, toluene, paraldehyde
  • Ketoacidosis (uncontrolled diabetes 1, alcohol intoxication, prolonged starvation)
  • Lactic acidosis (prolonged exercise, severe hypoglycemia, liver failure, heart failure, shock, severe anemia, thalassemia, sickle cell anemia)

Hypocalcemia

Symptoms: numbness and tingling around the mouth (circumoral paresthesia) and in the fingers, muscle spasms, constipation, lightheadedness ⁽³¹⁵⁾. Hypocalcemia can be caused by ^(315,316):

• Hyperventilation (see above)
• Parathormone (PTH) deficiency (hypoparathyroidism) due to disorders of the parathyroid glands
• Vitamin D deficiency in chronic intestinal, liver, bile duct, pancreatic or kidney disorders, lack of sunlight exposure
• Calcium malabsorption in celiac disease, Crohn’s disease, surgical removal of the stomach, gastric bypass (bariatric surgery) ⁽³¹⁷⁾, small intestinal bacterial overgrowth (SIBO) ⁽³¹⁸⁾
• Acute pancreatitis, acute kidney failure, blood transfusion, sepsis
• Severe malnutrition due to anorexia nervosa or chronic alcoholism
• Increased blood calcitonin levels due to thyroid disease, bone metastases
• Medications: furosemide (diuretic), omeprazole and cimetidine (gastric acid lowering drugs), phenobarbital (anticonvulsant), aminoglycoside antibiotics, amphotericin B, sodium phosphate (enema), chemotherapeutics, bisphosphonates, (for treatment of osteoporosis), foscarnet (for treatment of cytomegalovirus and herpes infections), fluoride overdose ⁽³¹⁾.

Hypokalemia

Symptoms: numbness in the fingers, muscle weakness and cramps ⁽³²⁸⁾.

Causes ⁽³³⁰⁾:

• Malnutrition, quick refeeding after prolonged starvation
• Prolonged diarrhea or vomiting
• Drugs: prolonged use of stimulant laxatives (senna), antacids (sodium bicarbonate), diuretics, steroids, beta adrenergic drugs (epinephrine, salbutamol, theophylline), fludrocortisone, antibiotics (penicillin), amphotericin B
• Excessive intake of natural licorice products
• Untreated diabetes type 1 with polyuria
• Adrenal gland tumors (hyperaldosteronism).

Hyperkalemia

Symptoms of hyperkalemia may include numbness, tingling, nausea, depression, irregular heart rhythm ⁽³³⁵⁾.

Causes ⁽³³⁵⁾:

• Ingestion of more than 18 grams potassium at once (potassium supplements, salt substitutes containing potassium chloride)
• Intravenous potassium overdose
• Drugs: certain diuretics (amiloride, spironolactone, triamterene), succinylcholine, trimethoprim-sulfamethoxazole, propofol (intravenous infusion), or an overdose of a heart medication digoxin, high blood pressure medications ACE inhibitors (captopril, enalapril), angiotensin receptor blockers or ARBs (losartan), beta-blockers (propranolol), nonsteroidal anti-inflammatory drugs or NSAIDs (aspirin, indomethacin, ibuprofen, naproxen), anticoagulant heparin, fluoride
• Kidney failure
• Adrenal gland insufficiency (Addison’s disease)
• Other: burns, head trauma, severe muscle damage, acute alcoholic myopathy (alcoholic rhabdomyolysis), hemolysis, advanced cancer.

Hypomagnesemia

Symptoms may include numbness and tingling, muscle cramps, loss of appetite, fatigue, seizures ⁽³³²⁾.

Causes of magnesium deficiency ⁽³³¹⁾:

• Malnutrition: chronic alcoholism or anorexia nervosa
• Impaired magnesium absorption: celiac disease, Crohn’s disease, surgical removal of a large part of the small intestine, pancreatitis, prolonged diarrhea, zinc supplements
• Excessive urination (polyuria): poorly controlled diabetes, kidney disorder, long-term treatment with diuretics or other medications
• Refeeding malnourished individuals with high amounts of carbohydrates
• Alcohol withdrawal
• Pregnancy and breastfeeding.

Hypophosphatemia

Symptoms of severe hypophosphatemia may include numbness, muscle weakness, double vision, problems with swallowing, bone pain ⁽³³³⁾.

Causes ⁽³³³⁾:

• Malnutrition
• Malabsorption due to use of large amounts of sucralfate, or aluminum, calcium or magnesium antacids, supplements or laxatives, Crohn’s disease, celiac disease, chronic diarrhea, vitamin D deficiency
• Drugs: diuretics, acetazolamide, bisphosphonates, chemotherapeutics (such as cisplatin), bicarbonate infusion
• Certain genetic kidney disorders
• Hyperparathyroidism
• Polyuria.

Hyponatremia

Symptoms of severe hyponatremia may include numbness and tingling in the limbs, confusion, headache, vomiting, muscle twitching ^(338,339).

Causes of severe hyponatremia ⁽³³⁹⁾:

• Adrenal insufficiency (Addison’s disease)
• Water intoxication after drinking large amounts of water (several liters) in a short time (“detox diet” or “water diet” in attempt to lose weight quickly, drinking plain water during marathon)
• Severe diarrhea or vomiting
• Certain diuretics
• Syndrome of inappropriate ADH secretion (SIADH), for example, in lung cancer.

Hypoglycemia

Symptoms of hypoglycemia (low blood sugar) may include anxiety, fast heartbeat, weakness, hunger, pale skin, sweating, shaking, tingling in the lips, hands and  fingertips, dizziness, blurred vision, seizures, passing out ⁽²¹²⁾.

Causes of hypoglycemia ⁽²¹²⁾:

• Diabetes 1: overdose of insulin, excessive exercise or skipped meals after insulin injection
• Diabetes 2: overdose of hypoglycemic medications, such as glipizide or glyburide
• Binge drinking without eating
• Reactive hypoglycemia after meals, which is common after a stomach bypass surgery
• Severe liver or kidney disease
• Disorders of the adrenal gland (Addison’s disease), pituitary gland (decreased secretion of the growth hormone), hyperthyroidism
• Medications: quinine (for malaria), propranolol (for heart disease), aspirin overdose, levofloxacin (an antibiotic)

Treatment of hypoglycemia ⁽²¹²⁾:

• In a conscious individual: glucose by mouth in the form of fruit juice, sugar cubes, raisins, crackers, glucose tablets
• In an unconscious individual: intravenous glucose injection or intramuscular glucagon injection

C. NEUROLOGICAL DISORDERS

Neurological disorders are the most common causes of numbness and tingling in the fingertips.

Sleeping Position, Numb and Tingly Fingertips in the Morning

Numb and tingly fingers in the morning can be due to sleeping with a hand under the head or other body part–the hand and fingers “fall asleep.”

• Numbness and tingling in the fingertips of the first three fingers can be due to sleeping with bent wrists; when the numbness does not go away within few minutes after getting up, it can be a part of carpal tunnel syndrome ⁽⁷¹⁾.
• Numbness and tingling in the pinky and ring finger(s) can be due to sleeping with bent elbow(s) or due to the pinky side of the wrist pressing upon a hard surface (like floor); symptoms persisting for more than few minutes may speak for cubital tunnel syndrome or hammer hand syndrome .

Blood Pressure Cuff and Blood Drawing

The pressure of the arm cuff during blood pressure measurement, or the pressure of the elastic band during blood drawing may cause temporary reduction of the blood flow and hence tingling in the hand and fingertips.

Spray Painting

Spray painting (pressing upon the spray can nozzle) for few hours may result in the numbness of the tip of the index finger lasting for several weeks, months or more than a year ⁽¹⁰⁶⁾. There is not much to do for numbness to go away, except avoiding pressure upon the affected fingertip. The numbness limited to one finger is likely caused by the damage of the small nerve endings in the fingertip and not due to spray poisoning.

Picture 2. The index finger on the spray can nozzle
(source: Flickr.com)

Cutting with scissors, carrying heavy plastic handle bags, gun shooting or anything other what presses upon the finger nerves can also result in numb fingertips lasting for few days.

Electrical Current

Holding a live wire with the electrical current intensity of 1-4 mA (milliamperes) can cause tingling in the fingertips, and 5 mA can cause a slight shock ^(51,108).

Finger Fracture

Sprain, strain or fracture of the finger may cause finger swelling, which may result in numb and prickly sensation in the fingertip ⁽⁸⁹⁾.

A Cut of the Digital Nerve

A cut on either side of the finger may break the digital nerve, which results in loss of sensation on the affected side of the finger distally to the cut. The distal part of the nerve dies off and the proximal part can then regrow into the denervated part at a rate about 1 mm a day (about an inch in a month), so after a cut on the base of the finger, it can take more than a month for sensation in the fingertip to come back ⁽⁹⁰⁾. Only shallow cuts can recover spontaneously; after deep cuts, surgery is required for proper regeneration of the nerve ⁽⁹⁰⁾.

Carpal Tunnel Syndrome (CTS)

Symptoms: Tingling (“pins and needles”), electric shock-like or burning feeling or pain in the tips of the first three fingers (thumb, index, middle) and the adjacent half of the ring finger (Picture 3), feeling of finger swelling (but usually no swelling), pain in the wrist; weaker grip, clumsiness of the hand, tendency to drop objects ^(2,71). Symptoms can appear suddenly or develop gradually and tend to worsen at night, when using a phone, reading a newspaper, driving a car or during any hand work. One or both hands can be affected but usually not symmetrically. Pain can radiate into the forearm, arm or even the shoulder. In chronic cases, numbness and decreased ability to differ between cold and heat by fingertips, and wasting of the muscles that move the thumb (thenar atrophy) can develop ⁽²⁾.

Mechanism: increased pressure upon the median nerve due to swelling of the tendon sheaths (tenosynovitis) in the narrow space in the wrist called carpal tunnel [Lat. carpum = wrist] ⁽²⁾.

Picture 3. Carpal tunnel syndrome
Yellow: areas with numbness or tingling

Causes and Risk Factors

• Often, the cause of carpal tunnel syndrome is not known ⁽²⁾
• Congenital narrowing of the carpal canal in mucopolysaccharidoses ⁽¹⁸⁷⁾
• Overuse of the wrist or repetitive strain injury due to assembly work, sewing, gardening, drawing, painting, computer use (typing), texting, piano, guitar, violin or cello playing, carrying heavy bags, cycling, riding a motorbike, tennis, golf, baseball, cricket, bowling, archery, fencing, basketball or handball training, weight lifting, jumping on a trampoline, etc. ^(2,68,71)
• Water retention (edema) during pregnancy (mainly in the 3rd trimester), in hypothyroidism, kidney failure, congestive heart failure, liver disease, protein malnutrition, cancer (kidney, liver, ovarian) ^(2,68)
• Lymphedema due to the axillary lymph nodes removal in women with breast cancer, or cancer of the lymph nodes (malignant lymphedema) ⁽²²⁵⁾
• Injury to the wrist, fractures of the wrist bones, finger joint dislocations ⁽²⁾
• Inflammation in the wrist: rheumatoid arthritis ⁽²⁶⁵⁾, gout, scleroderma, Lyme disease (borreliosis) ⁽²²⁷⁾, amyloidosis, multiple myeloma
• Ganglion cyst, mucous cyst or lipoma in the wrist ⁽²⁾
• Neuropathy (nerve damage) in diabetes or alcoholism ^(2,68).
• Drugs: contraceptive pills, corticosteroids, antihypertensives, NSAIDs, chemotherapy ⁽²¹⁷⁾, growth hormone ⁽³²⁰⁾.

Diagnosis

• Flick test: Shaking hands results in a temporary relief of symptoms ⁽⁶⁹⁾.
• Electromyogram (EMG), measuring of nerve conduction velocities (NCV) ⁽⁶⁹⁾
• X-ray, CT or MRI of the wrist, blood or other tests to find an underlying disorder may be needed ⁽⁶⁹⁾.

Conservative Treatment

• Wrist rest
• Wearing neutral wrist splints or braces at night or, even better, over 24 hours, physical therapy including wrist exercises and massage as recommended by a physiotherapist for each person individually ^(69,71)
• Oral corticosteroids ⁽⁷¹⁾ or
• steroid injections into the wrist ⁽⁷¹⁾
• Ultrasound therapy for several weeks ⁽⁶⁹⁾
• Treating the underlying cause ⁽²⁾

Nonsteroidal anti-inflammatory drugs (NSAIDS), such as ibuprofen, diuretics and vitamin B6 (pyridoxine) might be less effective ⁽⁷¹⁾.

Surgery

Surgical decompression of the wrist (open or endoscopic) is indicated when the above treatment does not work; permanent symptom relief is possible ^(2,3,69,71).

Prevention

Avoiding excessive wrist use, relaxing grip during cycling, frequent breaks during hand work, wearing wrist splints at night ⁽⁴⁾.

Guyon’s Canal Syndrome

Guyon’s canal is a bony canal on the palmar-pinky side of the wrist through which the ulnar nerve runs.

Entrapment of the ulnar nerve in the Guyon’s canal in the wrist can cause numbness and tingling of the 5th (pinky), adjacent side of the 4th (ring) finger and related side of the palm and wrist, muscle wasting on the pinky side of the hand and pain in the wrist ^(91,386).

Causes of Guyon’s canal syndrome include repeating prolonged pressure on the palms and gripping (cycling, weight lifting, using crutches, work with a jackhammer, manual work with wrists bent downwards and outwards), rheumatoid arthritis, osteoarthritis, wrist fractures, lipoma, ganglion cyst ⁽³⁸⁶⁾.

Treatment may include avoiding the cause, wearing wrist braces at night, anti-inflammatory drugs and surgery ⁽³⁸⁶⁾.

Cubital Tunnel Syndrome

Cubital tunnels is a bony canal on the side of the elbow that faces the body and through which the ulnar nerve runs.

Symptoms: numbness and tingling of the 5th (pinky), adjacent side of the 4th (ring) finger and related side of the palm and wrist, muscle wasting on the pinky side of the hand and, in chronic cases, weakness and clawing of the 5th and 4th finger, usually on one, but possibly on both hands, tenderness and pain on the inner side of the elbow ⁽⁹¹⁾.

Causes: pressure upon the ulnar nerve in the cubital canal of the elbow due to habitual leaning on the elbows (students), sleeping on bent elbows, long distance driving, frequent flexions and extensions of the elbow (golfers, guitar players, heavy manual work), anatomical anomaly (cubitus valgus, a complication of the elbow fracture), rheumatoid arthritis, osteoarthritis, subluxation of the ulnar nerve in the elbow, venepuncture, big hematoma ⁽⁹¹⁾.

Thoracic Outlet Syndrome (TOS)

Thoracic outlet syndrome is a group of symptoms caused by pressure upon the nerves, veins or arteries in the thoracic outlet–the space between the collarbone (clavicle) and the first rib. TOS may affect the left or right or both arms.

Neurogenic TOS

Cause: a damage of the nerves of the brachial plexus due to ⁽²³⁹⁾:

• Whiplash injury (car accident), motorbike accident, fall on the shouldr or head
• Static posture and repetitive movements of the arms in assembly workers, computer keyboard users, students

Symptoms ⁽²³⁹⁾:

• Pain in the neck, shoulder, chest, arm, forearm, hand and 4th and 5th finger
• Numbness and tingling in all fingers on the affected side, awakening at night
• Raynaud’s phenomenon
• Weakness of the arm or hand.

Burner Syndrome (Burner or Stinger) in Footballers

A burner is a transient, severe burning pain, tingling or numbness in the shoulder, which may travel down the arm up to the fingertips, and appears after a blow to or fall on the side of the shoulder or head; it occurs mainly in contact sports, such as football, rugby, hockey and wrestling ⁽³⁶¹⁾. Symptoms are probably due to stretching of the brachial plexus — a bunch of nerves that innervate the arm. Pain and numbness usually resolve within few seconds or minutes while arm weakness may persists for several days or longer ⁽³⁶¹⁾.

Lung Cancer and Pancoast Syndrome

Tumors on the top of the right or left lung that invades the chest wall are called Pancoast tumors. Symptoms may include pain in the shoulder that can radiate down the arm, swelling of the arm and hand, tingling in the little finger, flushing of one side of the face and a droopy eyelid and narrow pupil on one side (Horner’s syndrome) ⁽³⁸⁸⁾.

Cervical Radiculopathy (Pinched Nerve in the Neck)

Cervical radiculopathy–impingement of the spinal nerve roots in the neck–can result from cervical disc disease (herniated disc), cervical spondylosis (arthritis), whiplash injury, Paget’s disease or other disorder of the spine.

Symptoms may include pain in the neck, shoulder or arm, weakness in the arm, tingling or numbness in the hand or fingers, usually on one side, but sometimes on both sides. Symptoms may be aggravated by moving the neck or raising the arm. The distribution of numbness in the fingers depends on the spinal root affected ^(64,72,224):

• C6: The thumb and related part of the hand and forearm
• C7: The index and middle finger
• C8: The ring and little finger and related part of the hand

Sensation in the fingertips alone might be decreased, but this is not typical for cervical radiculopathy.

Cervical Spinal Stenosis

Cervical spinal stenosis is narrowing of the spinal canal through which the spinal cord extends; it can result in the compression of the spinal cord (myelopathy).

Symptoms may include numbness and tingling in the fingertips of both hands and feet, finger clumsiness and weaker grip, bladder and bowel incontinence ⁽³⁸⁷⁾.

Causes include congenital anomalies of the spine, arthritis, cervical spondylosis (degeneration due to wear and tear), herniated disc, injury of the cervical spine, tumors.

Treatment is usually surgical.

Peripheral Neuropathy (Polyneuropathy)

Peripheral neuropathy means damage of the peripheral nerves–sensory, motor and autonomic nerves that originate in the spinal cord and supply the limbs, trunk and internal organs. It usually occurs in older age.

Symptoms ^(55,60,144): slowly progressing (weeks, months) symmetrical tingling, tickling, tingling, prickling, stabbing or burning sensations, numbness and decreased sensitivity to temperature starting in the toes and feet and later in fingers and hands resulting in a “stocking and glove distribution.” Later, weakness and pain in the feet and hands, and urinary and fecal incontinence can develop. Allodynia (nonpainful stimuli feel like pain) and hyperalgesia (painful stimuli feel stronger than usually) can be present. Symptoms tend to be worse at night.

Causes ^{(55,56,57,58,60,61,63)}:

• Long-lasting diabetes 1 or 2 (diabetic neuropathy)
• Hypothyroidism (cold intolerance, weight gain), rarely hyperthyroidism
• Vitamin or mineral deficiency (in severe malnutrition, bariatric surgery):
  • Thiamine (B1) deficiency (beriberi with neuropathy and congestive heart failure, shiny skin, fatigue):
  • Niacin (B3) deficiency (pellagra with dementia, dermatitis with thick skin and diarrhea)
  • Vitamin B6 deficiency
  • Folate deficiency
  • Vitamin B12 deficiency in strict vegetarians and in individuals with atrophic gastritis (pernicious anemia with weakness and shiny red tongue–glossitis) and in nitrous oxide abuse
  • Vitamin E deficiency (rare)
  • Hypocalcemia (cramps, tingling in extremities) ⁽¹⁴⁴⁾
  • Hypophosphatemia (in individuals on parenteral nutrition)
  • Copper deficiency (after bariatric surgery)
• Alcoholism (alcoholic neuropathy)
• Idiopathic neuropathy–no known cause ⁽²⁵⁹⁾
• Chronic kidney failure with uremia (uremic neuropathy) ⁽¹⁴⁴⁾
• Autoimmune disorders: systemic lupus erythematosus (SLE) ⁽⁷⁷⁾, Sjögren’s syndrome ⁽²⁶⁴⁾
• Celiac disease (diarrhea after gluten-containing foods) ⁽⁶²⁾
• Paraproteinemia: amyloidosis ⁽¹⁸⁹⁾, multiple myeloma ⁽²⁷²⁾, Waldenstrom’s macroglobulinemia ⁽²⁰⁴⁾
• Certain cancers cause paraneoplastic sensory neuropathy
• Tick paralysis in children (weakness and numbness in legs progressing to arms and trunk) ⁽¹⁴⁵⁾
• Chronic obstructive pulmonary disease (COPD)
• Sarcoidosis ⁽²⁶³⁾
• Acromegaly
• Acute intermittent porphyria ^(183-p.16)
• Infections: diphtheria, hepatitis B and C, HIV/AIDS (feet), Lyme disease (2nd and 3rd stage) ⁽²⁶²⁾, neurosyphilis ^(144,261)
• Vasculitis: Churg-Strauss syndrome ^(144,257), microscopic polyangiitis ⁽²⁵⁷⁾, polyarteritis nodosa ⁽²⁵⁴⁾, Wegener’s granulomatosis ⁽²⁵⁷⁾, Takayasu’s arteritis ⁽²⁷³⁾, urticarial vasculitis ⁽²⁷⁴⁾
• Genetic metabolic disorders: Tangier’s disease ⁽³⁵⁹⁾, Refsum’s disease ⁽³³³⁾, Fabry’s disease ^(333,344)
• POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy and skin changes) ⁽²⁴⁶⁾
• Drugs: chemotherapy (hand-foot syndrome or palmar plantar erythrodysesthesia or PPE) ⁽¹⁴⁶⁾, antibiotics (isoniazid, metronidazole, nitrofurantoin, thalidomide) ⁽²⁶⁰⁾, antiretroviral agents in HIV/AIDS therapy (zidovudine, stavudine, lamivudine), antiepileptics (phenytoin), vitamin B6 overdose ⁽¹⁴⁴⁾, dapsone ⁽²⁶⁰⁾, disulfiram ⁽²⁶⁰⁾, heart medications (amiodarone, hydralazine, perhexiline) ⁽²⁶⁰⁾
• Toxins: acrylamide, allyl chloride, carbon disulfide, ethylene oxide, trichloroethylene, OPIDP, PCBs, PNU, organophosphates ⁽³⁴⁰⁾, n-hexane (glue sniffing) ⁽¹⁴⁴⁾
• Heavy metals: arsenic, gold, lead, severe mercury poisoning (Minamata disease) ⁽¹⁹⁴⁾, thallium. Arsenic and mercury may be in certain Chinese herbal medicines.

Treatment of polineuropathy may include:

• Treating the underlying cause
• Vitamin or mineral supplements
• Physical therapy: massage, acupuncture, transcutaneous nerve stimulation (TNS) ⁽⁵⁵⁾.
• Drugs: gabapentin, duloxetine and others

Prognosis depends on the severity of neuropathy; recovery may be incomplete ⁽⁶¹⁾.

Hereditary Neuropathies

• Charcot-Marie Tooth disease ⁽¹³⁹⁾
• Hereditary neuropathy with liability to pressure palsies (HNPP) ⁽¹³⁷⁾
• Hereditary sensory and autonomic neuropathy (HSAN) ⁽¹⁴⁴⁾

Leprosy

Leprosy (Hansen’s disease) is a rare chronic infectious disease. In the y. 2012, most infected people were in South Asia (mainly India and Indonesia), South America (mainly Brazil), Africa (mainly Nigeria), but also in the United States (mainly on the South), Mediterranean or other parts of the world ^{(136,220,221,222)}. It usually takes 2-3 years (range: 6 months to 40 years) for symptoms to appear after contact with an infected person ⁽¹³⁶⁾.

Symptoms ^(136,223):

• The first symptom can be loss of sensation (numbness) in the fingertips or toes. If treated early, sensitivity can be restored; if not, numbness can be permanent.
• Later–sometimes after years–pale or red splotches, bumps, plaques, lumps or ulcers can appear elsewhere on the skin; lesions may be numb or not.
• Muscle weakness
• The eyes, nose, throat, kidneys, testicles can be affected.

Leprosy can be cured. Treatment includes various antibiotics, oral steroids, thalidomide ⁽¹³⁶⁾.

Guillain-Barre Syndrome

Symptoms ⁽⁷⁵⁾: Symmetrical numbness and tingling can appear in the toes and progress to the ankles, or it can start in the fingertips and progress to the wrists; later, muscle weakness or even paralysis can rapidly (hours to days) progress and eventually affect the whole body; recovery usually occurs in the opposite direction. It may take several weeks or months to whole recovery.

Causes ⁽⁷⁴⁾: Guillain-Barre syndrome is an autoimmune disorder that can develop within a month after a common infection, such as cold or gastroenteritis.

Treatment and prognosis ⁽⁷⁴⁾: The disorder may be life-threatening and hospitalization is often required. Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) resembles Guillain-Barre syndrome, but has a chronic and recurring course.

Other Neurological Causes

• Multiple sclerosis ^(342,348)
• Seizures (grand mal epilepsy) ⁽³⁷³⁾
• Transverse myelitis (inflammation of the spinal cord) ⁽³³⁴⁾
• Chiari malformation is a congenital anomaly with protrusion of the cerebellum causing headache, incoordination, and numbness in the fingertips ^(205,206).
• Neurofibromatosis with light brown spots on the skin and nodules under the skin ⁽³²⁹⁾.

D. POOR CIRCULATION IN THE FINGERS

The blood flow in the fingertips may worsen suddenly (seconds to hours) or slowly (weeks to years).

SUDDEN Decrease in Circulation in Fingers

Causes: raised hands, blood clots, Raynaud’s phenomenon, vibration white finger, hypothenar hand syndrome.

Raised Hands

Sleeping with the hand(s) on the pillow or working with the hands above the level of the heart can reduce the blood flow in the hand(s) and cause transient paleness, tingling, numbness and weakness in the hand(s).

Bruise

After an injury, for example, with a hammer, the affected fingertip usually becomes tender and bruised: red, then  swollen and partially numb then dark blue-purple and then yellow-green.

Achenbach Syndrome

Achenbach syndrome (“paroxysmal hand hematoma” or “finger apoplexia”) ⁽³⁶⁸⁾ consists of sudden pain, itching, stinging, swelling, coolness, bruising and, sometimes, numbness on the palmar side of one or, rarely, more fingers that last for few days and then resolve spontaneously; this benign condition is due to spontaneous bleeding in the finger. Triggers include physical work with hands, minor trauma, exposure to cold. The affected individuals often have Raynaud’s phenomenon, migraine, chronic venous insufficiency (varicose veins), gallbladder disease, allergies or a blood disorder, such as anemia or thrombophilia. The condition may run in families. Blood and other tests are usually normal.

Blue Finger Syndrome

• The “acute blue finger” or “blue finger syndrome” ⁽³⁶⁰⁾. Some individuals experience sudden blue discoloration, coolness, swelling, pain (not always), numbness or “pins and needles” in one or more fingers without apparent reason ⁽³⁶⁰⁾. Symptoms may last for few days and rarely recur. Possible risk factors include smoking, atherosclerosis, Raynaud’s phenomenon, trauma, frostbite, thoracic outlet syndrome, cryoglobulinemia, polycythemia. The condition is often benign and the risk of thrombosis or embolism is low.

Blood Clot: Embolus

An embolus is a piece of coagulated blood or atherosclerotic plaque that originates at a certain site within the circulatory system, travels down the bloodstream and blocks the artery distally from its origin.

Symptoms: The affected fingertip suddenly becomes painful, pale or blue, numb, cold and eventually paralysed ^(251,353). If the radial artery in the forearm is blocked, there is no radial pulse in the wrist ⁽³³³⁾.

Origins of emboli:

• Atrial fibrillation (a type of heart arrhythmia) ⁽²⁵²⁾
• Heart valve disease: artificial valves, rheumatic fever, bacterial endocarditis ⁽²⁶⁷⁾
• Thrombus in the aneurism of the subclavian artery (arterial thoracic outlet syndrome) ^(239,242)
• Atherosclerosis in the arm or hand
• Acute disseminated intravascular coagulation (DIC)

Treatment with anticoagulants or surgical removal of an embolus should start as soon as possible, otherwise gangrene of the affected fingertip may develop ⁽³⁵³⁾.

Raynaud’s Disease and Raynaud’s Phenomenon

Mechanism: After brief exposure to cold, the artery spasm in the fingers shuts down the blood flow ⁽⁵⁾.

Symptoms: After exposure to cold–for example, taking food out of the freezer–or during stress, tips of one or more fingers on one or both hands become pale and then blue and then red (but not always in this order and not always all colors), numb, tingling, burning and often swollen and painful (a throbbing pain) ^(5,7,13). Discoloration is clearly demarcated from the normal skin ^{(12,16; Picture 4)}. The attack can last from less than a minute to several hours ⁽⁷⁾. The condition is also called “white finger,” “wax finger” or “dead finger.” Toes, nose, ears, lips or nipples can be also affected ⁽⁵⁾. Many individuals with Raynaud’s phenomenon have sweaty palms (hyperhidrosis) ⁽²⁷⁵⁾.  The condition is usually benign, but in severe cases, skin sores or gangrene can develop with time ⁽⁵⁾.

Picture 4. Raynaud’s phenomenon or syndrome
Two stages of Raynaud’s phenomenon: white and blue fingertips
(source: Commons.wikimedia.org)

Causes and risk factors ^{(6,8,9,15,16,140,237)}:

1. When the cause is not known (in 80% cases), the disorder is called Raynaud’s disease or primary Raynaud’s. It usually affects fingers on both hands. Symptoms often appear for the first time in the second or third decade of life. People with family history or living in cold climates are at higher risk.

2. Raynaud’s phenomenon or secondary Raynaud’s can be associated with the underlying diseases, such as:

• Systemic connective tissue diseases and autoimmune disorders: systemic sclerosis (scleroderma) and its subtype CREST syndrome (finger Calcinosis, Raynaud’s phenomenon, Esophageal dysmotility, Sclerodactyly (thick skin on the fingers) and Telangiectasia (dilated blood vessels in the skin) ⁽²⁴⁰⁾; Sjögren’s syndrome ⁽⁸⁾, systemic lupus erythematosus (SLE),  rheumatoid arthritis ⁽⁸⁾,  mixed connective tissue disease ⁽¹⁸⁶⁾, polymyositis/dermatomyositis ⁽¹⁹⁶⁾, antiphospholipid syndrome ⁽²⁴⁴⁾
• Atherosclerosis (after age of 50) ^(207,272)
• Vasculitis: polyarteritis nodosa ⁽¹⁹⁷⁾, Wegener’s granulomatosis ⁽¹⁹⁸⁾, rheumatoid vasculitis, lupus vasculitis, Buerger’s disease ^(142,207),
• Carpal tunnel syndrome
• Hypothenar hand syndrome ⁽²⁰⁷⁾
• Frequent piano playing, typing ⁽²⁰⁷⁾
• Vertebral disc disease ⁽²⁰⁷⁾
• Frostbite or electric shock may induce Raynaud’s phenomenon that lasts for years ⁽²⁰⁷⁾
• Hypothyroidism (myxedema)
• Kidney failure ⁽²⁰⁷⁾
• Primary pulmonary hypertension
• Thoracic outlet syndrome ⁽²⁷²⁾
• Thromboembolism ⁽²⁷²⁾
• Cancer–lung, ovarian and gastric cancer, carcinoid, lymphoma, leukemia, polycythemia–may cause “paraneoplastic acral vascular syndrome,” which may result in gangrene ⁽²⁶⁷⁾
• Prinzmetal angina (chest pain due to spasm of the coronary arteries)
• Liver disease: hepatitis B and C, primary biliary cirrhosis
• Paraproteinemia — abnormal proteins in the blood ⁽²⁷²⁾: cryoglobulinemia, POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy and skin changes) ⁽²⁴⁶⁾, primary amyloidosis ⁽³⁸²⁾
• Acromegaly (enlarged hands, feet and facial bones due to overproduction of the growth hormone)
• Blood hyperviscosity in polycythemia vera ⁽²⁷²⁾, Waldenström’s macroglobulinemia ⁽²⁰⁴⁾
• Haim-Munk syndrome, a rare genetic disease with red,scaly patches on the palms and soles, overgrowth of the fingernails, numbness and tingling in the fingertips, early loss of teeth ⁽²⁰³⁾.
• Acro-osteolysis–loss of terminal tufts in fingers–in scleroderma, sarcoidosis, leprosy, psoriasis, hyperparathyroidism, epidermolysis bullosa, hypertrophic osteoarthropathy, acrogeria, progeria, Reiter’s disease, Lesch-Nyhan syndrome, indifference to pain syndrome, mucolipidoses, malnutrition, osteomalacia, osteopetrosis, pityriasis rubra, porphyria, dermatomyositis/polymyositis, ectodermal dysplasia, Ehlers-Danlos syndrome^(208,216) and occupational acro-osteolysis due to exposure to vinyl chloride ⁽²⁰⁹⁾
• Syringomyelia ⁽²⁰⁷⁾
• Polyomyelitis ⁽²⁰⁷⁾
• Reflex sympathetic dystrophy ⁽²⁰⁷⁾

Possible triggers of arterial spasms ⁽²⁴⁴⁾:

• Exposure to arsenic, lead or vinyl chloride and organic solvents (toluene, acetone)
• Drugs: beta-blockers (propranolol), bromocriptine, chemotherapy (bleomycin, cisplatin, vincristine), clonidine, cyclosporine A, ephedrine, interferon alpha and beta, methysergide, migraine medications (ergotamine), oral contraceptives (estrogen), OTC cold medications, phenylephrine, pseudoephedrine, sulfasalazine ⁽²⁴⁴⁾.
• Smoking (in men) and heavy alcohol consumption (in women) ⁽¹³⁸⁾
• Amphetamine, cocaine
• Migraine headaches, medications for migraine.

Diagnosis: A doctor may order various tests to find an underlying cause.

Treatment and prevention ^(10,11):

• Keep sensitive areas warm, wear gloves and warm socks.
• Avoid smoking and caffeine since they constrict blood vessels and increase the risk of attacks.
• A doctor may prescribe calcium channel blockers (nifedipine), vasodilators (losartan, nitroglycerin cream), nitroglycerin ointment, sodium nitrate with ascorbic acid gel or, in severe cases alpha-blockers (prazosin, doxazosin), pentoxifylline or intravenous prostaglandins ^(10,272). Surgical treatment of the hand nerves is also available ⁽¹⁰⁾.
• During attack, you can hold fingers under warm (not hot) water, move your fingers and arms, massage your hands.
• Learn how to control stress
• Raynaud’s phenomenon may improve after menopause ⁽¹⁵¹⁾.

Other suggested treatments for Raynaud’s phenomenon, but insufficient scientific evidence:

• Fish oil with omega-3 fatty acids ⁽¹⁴⁾
• Antioxidants ⁽¹⁴⁾
• Ginkgo biloba extract ^(17,18)

Vibration White Finger

Hand-arm vibration syndrome (HAVS) or vibration white finger may develop in people who operate vibration machinery (jackhammers, sanders, power drills, chainsaws, pneumatic drills) ⁽³⁵²⁾.

Symptoms may develop in as little as one year, but usually after several years after onset of exposure to vibration and may include ⁽³⁵²⁾:

• Occasional numbness and tingling in one or more fingertips that can later extend to whole fingers and become permanent
• Weaker grip, difficulty fasting buttons, etc.
• Raynaud’s phenomenon with color changes (white-blue-red) in the fingertips (see above).

Prevention: Holding vibration tools as loosely as possible.

Other Causes Of Sudden Impairment of Blood Flow in Fingers

• Fractures of the bones and resulting damage of the arteries in the arm, hand or fingers
• Crush injury of the forearm, hand or fingers can cause swelling and numbness in the fingertips ⁽³⁵⁸⁾. Treatment is with urgent surgical decompression of the affected arm, hand or finger.
• Dissection of the thoracic aorta, which may block the blood flow into the subclavian artery ⁽¹⁵⁸⁾.
• Severe drop of blood pressure due to: cardiogenic shock (heart failure after heart attack or arrhythmia) ⁽²⁸⁶⁾, heart failure, dehydration, severe bleeding, sepsis
• Disseminated intravascular coagulation (DIC) after a snake bite or in malaria.
• Pheochromocytoma: cyanosis and tingling in the fingertips, finger tremor, pale skin, anxiety, high blood pressure ^(364,369)

CHRONIC Impairment of Circulation in Fingers

Symptoms ^(236,238):

• Numbness in the fingertips that slowly (months, years) progresses toward the hands
• Intermittent claudication: pain or cramping with repeated use of hands or raising them above the head (combing or washing hair); pain is relieved by the arm rest
• Raynaud’s phenomenon
• In severe cases, cold hands, bluish and slow-growing nails, lack of radial pulse, muscle wasting, shiny, scaly or cracked skin, ulcers or gangrene in the hands or fingers may develop.

Atherosclerosis (Arteriosclerosis)

Atherosclerosis [atheroma = fat-calcium deposits on the inner sides of the arterial walls; sclerosis = hardening] causes symptoms only in advanced stages when it starts to obstruct the blood flow ⁽²⁵¹⁾.

Main causes and risk factors of atherosclerosis: old age (after 50 for men, after 60 for women) ⁽²¹⁸⁾, increased blood cholesterol levels, high blood pressure, smoking, diabetes, obesity and physical inactivity, genetic factors ⁽²⁵¹⁾.

The progression of atherosclerosis can be slowed by avoiding risk factors. Symptoms of arterial occlusion can be partly prevented by avoiding cold temperatures and drugs that constrict arteries (ephedrine, ergotamine) ⁽²⁵¹⁾.

Treatment may include anticoagulants (aspirin, cilostazol, clopidogrel, pentoxifylline), artery dilators () and artery surgery (angioplasty, bypass, endarterectomy) ⁽²⁵¹⁾.

Vasculitis

Vasculitis is inflammation of the vessels. Symptoms of vasculitis may include fever, fatigue, joint pains, weight loss, skin rashes, ulcers on limbs ⁽³⁵⁵⁾.

• In rheumatoid vasculitis (in rheumatoid arthritis or systemic lupus erythematosus (SLE)),small rounded indentations (pits) and numbness in the fingertips may develop.  Red sores around the nails may be observed ^(356,358).
• Polyarteritis nodosa: numbness in the fingertips, livedo reticularis  (bluish net-like discoloration on the legs), nodules under the skin, purpura (red spots),  abdominal pain ^(255,270)
• Churg-Strauss syndrome may present with difficulty breathing (asthma) and red-bluish and numb fingertips ⁽²⁷⁶⁾.

Buerger’s Disease (Thromboangiitis Obliterans)

Buerger’s disease is an inflammation and narrowing of the small arteries and veins in the feet, legs or hands, which develops mainly in young male smokers; it can cause spasms in the calves during walking, spasms in the hands during manual work and numbness or tingling in the hands and feet; in severe cases, ulcers and gangrene in the fingertips or toes can develop ⁽¹⁴²⁾.

Arterial Thrombosis

Arterial thrombosis means abnormal blood clotting in the arterial blood. Causes and risk factors of arterial blood clots:

• Atherosclerosis ^(236,251)
• Aneurysm of the subclavian artery (arterial thoracic outlet syndrome) ⁽²³⁶⁾
• Buerger’s disease ⁽¹⁴²⁾
• Antiphospholipid syndrome ⁽²⁴³⁾
• Polycythemia vera (itchy skin, numbness in the hands and feet) ⁽²⁴⁷⁾
• Essential thrombocythemia (pain and bluish discoloration in the fingertips and toes) ⁽²⁴⁸⁾
• Thrombocytosis ⁽²⁴⁹⁾
• Thrombotic thrombocytopenic purpura (TTP) ⁽²⁶⁷⁾
• Disseminated intravascular coagulation (DIC) ^(231,267).

NOTE: Deep vein thrombosis usually does not cause numbness, but pain, redness, warmth and swelling of the affected part of the limb, usually the leg.

Venous Thoracic Outlet Syndrome

Cause: obstruction of the subclavian vein due to strenuous use of the arms and shoulders (baseball, swimming, weight lifting, work with elevated arms).

Symptoms: swelling and pain in the arm, bluish discoloration (cyanosis) and paresthesia in the hand and fingers ^(239,333).

Cryoglobulinemia

Cryoglobulinemia means the presence of antibodies called cryoglobulins in the blood. At low temperatures, cryoglobulins clump together with other blood proteins and block the small arteries ⁽³⁵⁶⁾.

Cryoglobulinemia can be associated with viral infections (hepatitis A, B or C, EBV, CMV, HIV), streptococcal infections, endocarditis, kidney disease (glomerulonephritis), dermatomyositis, syphilis, Lyme disease, brucellosis, Q fever, leprosy, coccidioidomycosis, autoimmune disorders (rheumatoid arthritis, SLE), multiple myeloma, lymphoma, leukemia ⁽²⁴⁵⁾, Waldenström’s macroglobulinemia ^(204,284)

Symptoms may include Raynaud’s phenomenon, purpura causing bright red circles (1-15 mm) on the skin, numbness in the fingers, muscle pains, blood in urine, ulcers, abdominal pain, chest pain ^(245,356).

Fibromuscular Dysplasia

Fibromuscular dysplasia is a disorder of unknown cause with narrowing of medium-sized arteries. It occurs mainly in women in childbearing age ⁽²⁵⁰⁾. Symptoms may include headache, abdominal pain and numbness in limbs ⁽²⁵⁰⁾. Treatment may include anticoagulants and surgery ⁽³⁴⁶⁾.

E. Hypoxia, Cyanosis

Hypoxia means lack of oxygen in the air, blood (hypoxemia) or in the body tissues (tissue hypoxia). Hypoxia can cause “central cyanosis.”

CENTRAL Cyanosis

Central cyanosis is caused by decreased oxygenation of the blood and this may be (not always) associated with hyperventilation and tingling in the fingertips. Hands and feet, especially nail beds, lips, gums and tongue are bluish but not cold (unless the causes of peripheral cyanosis are also present) ⁽³⁷²⁾.

F. SKIN DISORDERS

Thick or peeling skin on the fingertips may cause numbness.

Callus, Frictional Dermatitis, Warts, Scars

Beginner guitar, violin, cello, harp (harpist’s finger) and bass players firstly have tender and sore fingertips, but, within a week or two of regular playing, they develop thick skin (calluses), which are slightly numb ^(104,128). Calluses can be removed by soaking the fingers in hot water, drying them up and gently rubbing them with a pumice stone.

Repeated use of a hammer or other hand tools, pen-spinning, rock climbing, rowing, cycling, gymnastic exercises, weight-lifting and bowling can also cause calluses or corns on the fingertips.

In diabetics, frequent pricking of the fingertips for blood testing may cause calluses ⁽¹⁰⁷⁾.

Frictional contact dermatitis with calluses on the fingertips and hands in workers who handle large amounts of paper, cardboard, fabric or small plastic or metal objects can develop within months or years of exposure ^{(114,115,116)}. Dermatitis may be healed within 2-3 weeks after cessation of friction ⁽¹¹⁷⁾.

Common skin warts are also numb.

Scar tissue can be permanently numb but some sensitivity may return with time. The tissue around the scar can be also temporarily numb ⁽³²¹⁾.

Fingertip Infection

• Felon or a staphylococcal whitlow or cellulitis of the fingertip is an abscess in the fingertip pulp–the fleshy part of the fingertip. It usually occurs on the thumb or index finger due to a splinter or puncture wound, such as blood testing (in diabetics). The fingertip is initially red and painful and can eventually swell and become numb ^(162,163).

Treatment includes antibiotics and drainage ⁽¹⁶²⁾. In severe cases, necrosis (gangrene) may develop ⁽¹⁶²⁾.

Finger Herpes (Herpetic Whitlow)

Symptoms ⁽²³⁾: a red swelling with tingling, burning sensation on one or more fingertips, followed by small (1-3 millimeters), translucent, yellowish, itchy or painful, fluid-filled blisters in clusters. Blisters usually burst and crust over and heal completely within 2 weeks. Low-grade fever or malaise can precede blisters. A red line (inflamed lymphatic vessels) going up to the arm toward the lymph nodes may be seen.

Picture 5. Herpetic whitlow
Left: deep red sore in the fingertip
Right: white blisters with red halo
(source: Intechopen.com)

Cause ⁽²³⁾: the contact with Herpes simplex virus, either oral (HSV-1), causing “cold sores,” or genital virus (HSV-2). First symptoms may appear within 2-20 days after contact with the virus.

Who gets affected? Dentists and other health care workers, children who suck thumbs, or anyone who gets in contact with saliva or infected skin of other people. After the primary infection, Herpes virus remains in the body in the latent state and can be reactivated by stress, exposure to sun, illness, surgery, trauma, hormonal changes (menstruation, pregnancy, etc.) ⁽²³⁾.

Treatment and prevention ⁽²³⁾:

• Cover the affected area with a bandage to prevent spreading to other body parts or transmission to other people, since the virus is very contagious.
• A doctor can prescribe acyclovir ointment or pills or other antiviral drug. Taking these medications after the onset of tingling, but before blisters, can prevent the development of blisters.

Fingertip Eczema, Dermatitis (Pulpitis)

Fingertip eczema is a form of irritant contact dermatitis (or allergic contact dermatitis or atopic dermatitis); it may affect only the fingertips or the whole palm (hand dermatitis) ⁽³⁰⁾. Symptoms ^{(24,131; Picture 6)}: The skin on one or more fingertips or a part of the palm becomes hard and numb, then starts to peel in large, thick flakes; the fingertip becomes tender, cracked, red and painful, but not itchy, and then heals on its own; the whole cycle can last 3-4 weeks and can keep occurring on the same or other finger.

Picture 6. Fingertip eczema
Peeling and cracks on the fingertip
(source: Intechopen.com)

Causes and risk factors ^{(26,27,28,29,97)}:

• The exact cause is not known; it may be associated with other types of eczema, contact dermatitis (including protein contact dermatitis), allergic contact dermatitis, atopic dermatitis or allergy.
• Triggers include irritant plants, such as garlic causing “garlic dermatitis” (in housewives, chefs) ⁽²⁸⁾, tulip bulbs causing “tulip fingers” ⁽⁹⁷⁾, chili pepper ⁽¹¹³⁾, acrylic nails ⁽²⁵⁾; acrylic materials (bone cement–orthopedic surgeons), glutaraldehyde, rubber and resins (used by dentists) ⁽²⁹⁾; thimerosal, colophony, nickel-plated tools (in car mechanics) ⁽²⁶⁾; prolonged contact with paper or cardboard ⁽²⁸⁾; water, soaps, disinfectants (in nurses), shampoos, perfumes ( in hairdressers), detergents, solvents, lubricants, oils, coolants, fiberglass dust, food products (fruits, vegetables, raw meat, fish), rubber latex (surgical gloves), metals and plastics; antibiotics or stress ⁽³⁰⁾. Bricklayers, florists, gardeners, farmers and janitors often have fingertip eczema.

Diagnosis ⁽³⁰⁾: Patch tests and other tests to find eventual allergy.

Treatment ^(30,37,39):

• A doctor may prescribe steroid creams (clobetasol), steroid foams, pimecrolimus, tacrolimus; alitretinoin, zinc oxide.
• Phototherapy (PUVA)

Prevention: Avoid triggers, wear vinyl gloves. Use moisturizing creams to keep hands moist.

Focal Palmar Peeling (Exfoliative Keratolysis)

Air-filled blisters appear on the palms and fingers. Blisters burst and leave areas of flaky, red, but usually not itchy, skin. In the fingertips, cracks and numbness may appear. Frequent contact with water, soap, detergents or solvents may worsen symptoms. The condition has no known cause; young adults with palmar hyperhidrosis are often affected. Moisturizing creams containing urea or lactic acid and photochemotherapy (PUVA) may help ⁽³²⁴⁾.

Nail Fungus (Onychomycosis)

Some individuals with nail fungus who have yellowish, pitted or cracked nails, may experience prickling or tingling in the fingertips ^(134,135).

Picture 7. Nail fungus (onychomycosis)
(source: Phil.cdc.gov)

 

Burns and Scalds

• Immediately after a deeper second-degree burn or scald (a part of skin thickness involved in kitchen burns, oven burns), the affected area is very sensitive, pink or red, with blisters and a possible “pins and needles” sensation ^(45,48). Later, blisters peel off and sensitivity to pain may be temporarily reduced ⁽⁴⁸⁾ for up to a month.
• Third-degree burn or scald (all skin layers affected) may result in white, leathery skin and permanent loss of sensation to touch and pain, or gangrene ^(46,47).
• Fourth-degree burn causes tissue death (gangrene) with bluish-black and numb fingertips ⁽⁴⁶⁾.
• Several months after the burn injury, pins and needles, burning, stabbing, shooting, “electric” sensations may appear and may persist for more than a year ⁽⁴⁴⁾.
• Chemical and caustic burns: hydrofluoric acid ⁽¹⁰⁰⁾
• Electric burns may cause temporary numbness and “pins and needles” sensation ⁽⁵⁰⁾. In severe cases, permanent loss of sensation, limited to the area of direct contact with the electrical source, can occur ⁽⁵⁰⁾.

First aid ⁽⁴⁹⁾:

• Remove the source of heat.
• Hold the burnt area under cool or lukewarm tap water for 10-30 minutes. Never apply ice or any cream.
• Over the counter (OTC) oral painkillers, such as paracetamol or ibuprofen.

Exposure to Cold

Exposure to freezing temperatures can cause finger stiffness, clumsiness and numbness to touch or pain even before any cold injury occurs ^(380,383).

Chilblains (Perniosis)

Symptoms ^{(118,120,121)}: Exposure of the hands to non-freezing temperatures below 60 °F (16 °C) for as little as one hour can cause red papules and pain; reheating results in reddish or bluish discoloration and swelling of the fingertips or toes, which may be hot, painful, burning, itchy, tingly or numb.

Chilblains usually recovers on its own within 1-3 weeks but, sometimes, only after few months or years; hyperhidrosis, numbness and cold sensitivity may persist for a long time.

Cause: damage of the arteries (vasculitis) in the fingers or toes due abnormal reaction to cold and subsequent reheating. Individuals with Raynaud’s disease, systemic sclerosis and systemic lupus erythematosus (SLE) are at greater risk.

First  aid. Immersion of the affected body part in warm water at 98-104 °F (37-40 °C). NOTE: Do not massage, pop blisters or apply ointments.

Picture 8. Chilblains on the fingers
(source: Commons.wikimedia.org)

Frostnip

Frostnip is a first-degree frostbite without any permanent damage of the tissues; it is caused by exposure to freezing temperatures.

Symptoms ⁽¹²¹⁾: Hands and fingers are initially blue-gray or pale, cold, numb, tingly and stiff and later–with thawing–become red and painful, especially at the fingertips. Quick reheating by massaging the hands or holding them in warm pockets or under the armpits usually causes numbness to go away within few minutes. Swelling may appear within 2-3 hours after thawing and may persist for 10 days. Skin may peel off in 5-10 days. Tingling may persist for some time.

Frostbite

Frostbite is a tissue damage due to exposure to freezing temperatures.

Symptoms ^(121,125):

• Second-degree frostbite: The skin is cold and may be numb, tingly, burning, white, waxy and firm to the touch (“wooden feeling”); there is little pain and loss of sensation; blisters with clear fluid appear in 12-24 hours; after reheating, throbbing pain may persist for 3-10 days. Complete recovery without permanent tissue loss usually occurs in 3-4 weeks. Sensitivity to cold may persist for a longer time.
• Third-degree frostbite: The affected finger is numb; blisters are blood-filled; swelling may persist for 5-6 days, superficial skin forms a black and hard eschar, which peels off and may cause ulcers; some skin tissue may be permanently lost; burning, throbbing pain may persist for 5 weeks; cold sensitivity and numbness are common and may persist for years. Persistent cyanosis and numbness after rewarming are bad prognostic signs ⁽³⁸⁵⁾.
• Fourth-degree frostbite: The finger is not mobile; there is no swelling or blisters. After reheating, cyanotic color appears. In freeze-thaw-refreeze injuries, dry gangrene with mummification occurs within 5-10 days; after slow freezing, gangrene develops within a month, the affected part eventually falls off.

First aid ^{(121-p.58;122)}: Immersion of the affected fingers in warm water at 98-104 °F (37-40 °C) for 30-45 minutes until they appear flushed, or heating by the body heat (hands under clothes). No massage. Do not thaw if refreezing is possible.

Cold Burn

Cold burn is frostbite (anything from the first to fourth-degree) caused by contact with cold objects ⁽¹²⁵⁾:

• Ice pack applied directly to the skin for 20 minutes can cause second-degree frostbite, which may need several days to heal ⁽¹²⁶⁾.
• Dry ice (frozen carbon dioxide) applied directly on the skin can cause third-degree frostbite ⁽¹²⁷⁾.
• Liquid gases, such as liquid nitrogen, liquid oxygen, liquefied petroleum or propane-butane gas may cause severe cold burn ⁽¹²⁴⁾.

Heart Disease and Numbness

An individual with heart disease may experience occasional numbness in the fingertips. However, numbness alone in a person who does not have a history of at least one of characteristic symptoms of heart disease, such as pain behind the breastbone triggered by physical effort or stress, irregular heart beats, weakness, shortness of breath or bluish fingers, does not likely speak for heart disease.

• Heart attack may be preceded by numbness, tingling or pain in the left, right or both arms and hands ^(287,288). Someone who has a heart attack probably has a history of angina pectoris (heart-related chest pain), which may be also accompanied by numbness in the arms ⁽²⁸⁹⁾.
• Individuals with acute or chronic heart failure from various reasons often have pale or bluish and numb fingertips.

G. OTHER CAUSES

• Hypoxia with central cyanosis, acrocyanosis, hypothenar hand syndrome
• Migraine aura (numbness starts in the fingers and travels up to the arm and to the face) ^(144,333)
• Basilar migraine (numbness in both arms or legs ⁽²¹⁹⁾
• Fibromyalgia ^(165,333)
• Carbon monoxide poisoning (acute or chronic) ⁽³³⁴⁾
• Marijuana overdose (numbness in arms and hands, and sometimes legs or head, can last for more than a week) ⁽¹⁸¹⁾
• Radiation exposure may result in chronic progressive radiation damage of the spinal cord (myelopathy) ⁽³³³⁾ or brachial plexus (treatment of breast cancer) ⁽³⁸⁴⁾; symptoms may appear months or years after radiation exposure.
• Anaphylactic reaction ⁽³⁴⁴⁾
• Pheochromocytoma (epinephrine-secreting carcinoma of the adrenal gland) ^(364,369)
• Hypoparathyroidism may present with numb and scally fingertips ⁽³²²⁾.