Hyperhidrosis (Excessive Sweating)

Hyperhidrosis is a medical term used to describe the condition of excessive and uncontrollable sweating.

Sweat is a weak salt solution that is naturally produced by the eccrine sweat glands. Eccrine sweat glands are found all over the body, especially on the palms and soles.

Hyperhidrosis can be identified as either localized, affecting the armpits, soles, palms, or face, or generalized, affecting most or all of the body. It can be primary or secondary in nature.

Primary Hyperhidrosis

Primary hyperhidrosis results from the overactivation of the hypothalamic thermoregulatory centre in the brain. It is transmitted through the sympathetic nervous system into the eccrine sweat glands. The condition begins during childhood or adolescence. It can be persistent throughout the entire lifespan or may improve with age. Primary hyperhidrosis can be inherited and passed from one generation to another. The armpits, soles, or palms are affected symmetrically. Triggering agents of sweating attacks include exercising, anxiety, hot weather, fever, and spicy food. Sweating attacks typically decrease at night and disappear during sleep.

Secondary Hyperhidrosis

Secondary hyperhidrosis is less common than primary hyperhidrosis and can occur at any age. It is not symmetrical and can occur at night or during sleep. The condition is generally caused by neurological or endocrine conditions.

Secondary localized hyperhidrosis may be triggered by the following causes:

• Spinal nerve damage
• Stroke
• Peripheral nerve damage
• Brain tumour
• Neuropathy
• Chronic anxiety disorder

Secondary generalized hyperhidrosis may be caused by the following conditions:

• Obesity
• Menopause
• Diabetes
• Respiratory failure
• Overactive thyroid
• Cardiovascular disorders
• Parkinson's disease
• Hodgkin lymphoma

Certain drugs, including caffeine, alcohol, tricyclic antidepressants, opioids, and nicotinamide, may also lead to secondary generalized hyperhidrosis.

Impact on Daily Life

Hyperhidrosis tends to interfere with many daily activities and negatively affects quality of life. During axillary hyperhidrosis, clothing becomes damp and stained, requiring multiple changes throughout the day. Wet skin folds may be affected by further medical conditions, such as infection, irritant dermatitis, and chafing.

Palmar hyperhidrosis causes slippery hands, leaves marks on paper and fabrics, and may lead to avoidance of handshaking. Difficulties are also experienced when using electronics such as trackpads and keypads, and neat writing may not be possible.

Plantar hyperhidrosis affects the soles of the feet, causing an unpleasant odour and damage to footwear. It may also lead to a blistering type of dermatitis and secondary infection.

Diagnosis

Hyperhidrosis is diagnosed clinically and requires a dermatologic consultation. Localized hyperhidrosis is tested through the Minor test. The test begins by applying iodine to the patient's skin and allowing it to air dry. Starch is then dusted over the iodine. Sweating is revealed when the colour changes to a dark blue-black colour.

Secondary generalized hyperhidrosis requires consideration of other clinical features during diagnosis. For example, blood sugar and thyroid function tests may be requested by a dermatologist.

Treatment Options

Numerous treatment methods are available for hyperhidrosis. Many topical antiperspirants are available on the market, and a variety of oral medications may be prescribed as part of a course of treatment. Botulinum toxin injections are medically approved for the treatment of hyperhidrosis and have demonstrated effective results in reducing excessive sweating.