What is Palmar Hyperhidrosis?

Sweaty palms, medical term palmar hyperhidrosis, refers to profuse perspiration (excessive sweating) of the palms. Palmar hyperhidrosis is one form of focal hyperhidrosis, meaning profuse perspiration affecting one area of the body. Sweaty palms may be accompanied by profuse perspiration of the feet, forehead, ckeeks, armpits (axillae) or be part of general hyperhidrosis (profuse perspiration throughout the body). Hyperhidrosis refers to profuse perspiration beyond the body’s thermoregulatory (temperature control) needs. A Greek term for hyperhidrosis is diaphoresis.

Symptoms of Palmar Hyperhidrosis

The intensity of symptoms may vary among sufferers and trigger factors should be carefully noted. Common symptoms include :

  1. Perspiration of the hands can vary from mild clamminess to severe perspiration resulting in dripping sweat.
  2. Temperature differences of palmar surface compared to surface temperature of other parts of the body may be noted.
  3. Sloughing (peeling) of skin may be noted in profuse perspiration.
  4. Episodes of profuse perspiration may be followed by periods of extreme dryness on the palmar surface.
  5. Hyperhidrosis often starts in puberty, and family history is often reported (4).

The secondary effects of palmar hyperhidrosis can result in both psychosocial effects as well as difficulty in undertaking certain tasks or handling equipment. Sufferers of palmar hyperhidrosis are often reluctant to partake in socially expected actions like shaking hands or touching loved ones. The embarrassment of dealing with this condition can affect the level of interactivity in both social and work situations. Difficulties with holding objects, gripping equipment or soiling electronic devices like keyboards may affect functioning at work. Daily activities such as writing with a pen or counting cash notes is often difficult.

What Causes Palmar Hyperhidrosis?

Hyperhidrosis is either primary focal or secondary generalized (5).

1. Primary Palmar Hyperhidrosis

Focal palmar hyperhidrosis is usually localized and is referred to as primary (essential, idiopathic), meaning no obvious cause, except strong family predisposition can be found (4,5), and affected persons are otherwise healthy (4). Sweating on other locations as feet, armpits and face may appear. Primary palmar hyperhidrosis is caused by overactivity of the sympathetic nervous system, primarily triggered by emotional causes including anxiety, nervousness, anger and fear (3).

There may be a significant reduction in perspiration during sleep or sedation (3).

2. Secondary Palmar Hyperhidrosis

In secondary palmar hyperhidrosis hands sweat due to an obvious underlying disorder like:

  1. Infections including local infections, tuberculosis and tinea ugunium.
  2. Neurological disorders like peripheral autonomic neuropathy 
  5. Acromegaly
  7. Complex Regional Pain Syndromes
  11. Blue rubber-bleb nevus
  12. Glomus tumor
  13. Secondary palmar hyperhidrosis as part of generalized hyperhidrosis due to (3,5): hormonal causes (diabetes, hyperthyroidism, thyrotoxicosis, menstruation, menopause), metabolic disorders, malignant disease (lymphoma, pheochromocitoma), autoimmune disorders (rheumatoid arthritis, systemic lupus erythrematosus), drugs like hypertensive drugs and certain classes of antidepressants (list of medications causing hyperhidrosis), chronic use of alcohol, Parkinson’s disease, neurological disorders (toxic neuropathy), homocystinuria, plasma cell disorders. Detailed list of conditions causing generalyzed hyperhidrosis.

How Sweat Glands Work

In eccrine glands, the major substance enabling impulse conduction is acetylcholine, and in apocrine glands, they are catecholamines.

Body temperature is controlled by the thermoregulatory center in the hypothalamus and this is influenced not only by  by core body temperature but also by hormones, pyrogens, exercise and emotions (9).

Interesting Details About Physiology of Sweating

Mechanism of Focal Hyperhidrosis

Sweat is produced by the sweat glands that are under the control of the autonomic nervous system, the involuntary neural network. Our conscious effort may be able to exert some influence on the autonomic nervous system as emotions have been noted to increase sweat production. The autonomic nervous system is broadly divided between the sympathetic and parasympathetic nervous system. The sympathetic nervous system is usually seen as the activity system which stimulates functioning of different parts of the body. In cases of primary palmar hyperhidrosis, it is the overactivity of the sympathetic nervous system that is responsible for the excessive sweating. The increased rate of neural impulses to the sweat gland for no known reason stimulates the gland to constantly produce more sweat. There is no histological changes noted in primary palmar hyperhidrosis meaning that the number and size of sweat glands is as normal (4).

Only eccrine sweat glands that secrete odourless sweat are involved in focal hyperhidrosis (4). Apocrine glands – scent glands found mainly in axilla and genitalia - are stimulated by sex and other hormones and are not involved in focal hyperhidrosis (4).

There is evidence that these patients have a reduced threshold for emotional sweating but have normal thermoregulatory processes and drug-induced sweating (6).

There is a vicious cycle that can occur with excessive palmar and plantar sweating—the evaporative cooling of the skin increases sympathetic outflow through reflex action, in turn increasing sweat output (10).

Primary hyperhidrosis may involve parasympathetic pathway differences as well (10).

Additional Details About Patophysiology of Excessive Sweating

Investigating Palmar Hyperhidrosis

The first step in the evaluation of hyperhidrosis is to differentiate between generalized and focal hyperhidrosis.

A thorough case taking and medical history is usually sufficient to diagnose palmar hyperhidrosis and any trigger factors (scheduled drugs, narcotics, chronic alcoholism).

Diagnostic criteria for primary focal (including palmar) hyperhidrosis include (4):

  • Bilateral and relatively symmetric sweating
  • Frequency of at least 1 episode per week
  • Impairment of daily activities
  • Age at onset before 25 years
  • Family history
  • Cessation of sweating during sleep

Tests may include:

  • Hematological studies may be necessary to identify thyroid disorders (thyroid function test for T3 and T4 as well as thyroid antibodies) and diabetes (fasting blood glucose or a glucose tolerance test).
  • X-rays and MRI scans will assist for diagnosing tuberculosis, pneumonia and tumors.
  • Superficial electroconductivity can be monitored as any hyperhidrosis reduces skin electrical resistance.
  • Thermoregulatory sweat test uses moisture-sensitive indicator powder to monitor moisture. Changes in the color of the powder at room temperature will highlight areas of increased perspiration.

Conservative Management of Palmar Hyperhidrosis

Conservative management should be coupled with prescribed treatment by a medical practitioner to reduce the symptoms.

  • Counseling may be effective in managing primary palmar hyperhidrosis in cases of mental-emotional etiology.
  • Trigger foods and aggravating factors should be noted if possible and relevant dietary changes should be implemented.
  • Effective prevention of secondary palmar hyperhidrosis is difficult with conservative management and drug therapy or surgery may be required.
  • Excessive physical activity and extremes of heat may be two trigger factors that should be avoided as far as possible.
  • In cases of diabetes, a glucose controlled diet with low glycemic index may improve glucose tolerance which could assist with palmar hyperhidrosis.
  • Abstinence from alcohol and narcotics is advisable if it is the causative factor for sweaty palms.
  • Stimulants such as caffeine and nicotine may aggravate palmar hypehidrosis and should relevant dietary and lifestyle changes should be implemented.
  • Anti-perspirant compounds like aluminum chloride can be applied on the palms to reduce moisture or palmar surfaces. Recent research on an aluminum sesquichlorohydrate foam has shown that it is effective in reducing sweat in palmar hyperhidrosis (2).

Treatment of Palmar Hyperhidrosis

Standard therapeutic protocol may differ among cases of palmar hyperhidrosis depending on medical history and underlying pathology.

  1. Anticholinergic drugs have a direct effect on the sympathetic nervous system although there are numerous side effects.
  2. Treatment should be directed at contributing factors.
  3. Ionophoresis involves the use of electrotherapeutic measures to reduce the activity of sweat glands.
  4. Botulinum injections at the affected area may be useful for its anticholinergic effects.
  5. Surgery should be considered if drug therapy proves ineffective. Endoscopic transthoracic sympathectomy involves resection of the sympathetic nerve supply to the affected area. This prevents nerve stimulation of the sweat gland of the palms. However surgery has a host of complications including exacerbating the problem or increasing generalized hyperhidrosis (3). 

Possible Approach to Primary Palmar Hyperhidrosis

It has been reported many times that excessive sweating in focal hyperhidrosis (including palmar hyperhidrosis) was triggered by “emotional stimuli” (3,5).

It seems like persons with primary hyperhidrosis have their sympathetic nervous system in a constant “on” position (8). Considering that no neural disorder on a biochemical, histopathological or any other physical level, except sympathetic overactivity itself was found, it seems reasonable to surmise that this high sympathetic tone is being constantly influenced by impulses from cerebral cortex, specifically from the frontal lobe. The frontal lobe of the cerebral cortex is responsible for thought processes, meaning from the affected person’s own will. Connections among lymbic system (responsible for emotions), hypothalamus and sweat glands are also known. 

It seems reasonable that a particular thinking pattern causes constantly increased sympathetic tone in a person with hyperhidrosis. It is therefore possible to expect that changing this thinking pattern can help to lower sympathetic activity below the point where everyday stress would not trigger sweating.

Changing attitudes to life experiences, improving coping skills and resolving interpersonal relationship issues in order to remove or reduce emotional stress could assist the condition accordingly. Counselling by experienced persons and a discipline, that includes sticking with some good habits and resisting from others (generally known as fasting) is usually needed. Undisciplined attempts with dietary changes and various “exercises” alone don’t seem to be enough to cure primary hyperhidrosis though. 

Related Topics:

Tingling Hands and Fingers
Itchy Arms and Hands
Acrylic Nails – Nail Fungi    

References:

  1. Sweaty palms syndrome may run in families (universityofcalifornia.edu)
  3. Hyperhidrosis causes (emedicine.com)
  7. Hyperhidrois epidemiology (sweathelp.org)
  9. Hölzle E. Pathophysiology of sweating. Curr Probl Dermatol. 2002;30:10-22.
  10. Sato K, Kang WH, Saga K, Sato KT. Biology of sweat glands and their disorders. II. Disorders of sweat gland function. J Am Acad Dermatol. 1989;20:713-726.

Further Reading :
  • Itchy Armpits – Causes and Symptoms
  • Acrylic Nails Health Problems – Nail Fungi
  • Excessive Belching, Burping and Bloating – Causes and Treatment