Hyperhidrosis is the name given to excessive and uncontrollable sweating.

Sweat is a weak salt solution produced by the eccrine sweat glands. These are distributed over the entire body but they are most numerous on the palms and soles (with about 700 glands per square centimetre).

• Localised hyperhidrosis may affect the armpits, palms, soles, face or elsewhere.
• Generalised hyperhidrosis may affect the entire body.

Localised hyperhidrosis is more common than generalised hyperhidrosis. Triggers to attacks of sweating may include:

• Hot weather
• Exercise
• Fever
• Anxiety
• Spicy Food

The sweating usually reduces at night time and disappears during sleep.
Hyperhidrosis of palms and soles

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What is the cause of hyperhidrosis?

The exact cause or causes of hyperhidrosis are unknown. It appears to be due to overactivity of the body temperature centre in the brain (the hypothalamus) or of the sympathetic nerves that control the sweat glands.

Primary hyperhidrosis first appears in childhood or adolescence. It may persist lifelong, or improve with age. Other family members may or may not be similarly affected. It tends to involve both armpits, palms and or soles symmetrically.

Secondary hyperhidrosis as a consequence of a medical disease or condition is less common. Secondary hyperhidrosis is more likely to be unilateral and asymmetrical, or generalised. It can occur at night or during sleep. It may be due to endocrine or neurological conditions, such as:

• Obesity
• Diabetes
• Menopause
• Overactive thyroid
• Cardiovascular disorders
• Respiratory failure
• Other endocrine tumours
• Parkinson's disease
• Drugs

Localised hyperhidrosis may also be due to:

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

What is the result of excessive sweating?

Hyperhidrosis is an embarrassing complaint and significantly interferes with many daily activities.

Armpits:

• Clothing becomes damp and unsightly and must be changed several times a day.
• Wet skin folds are prone to chafing, irritant dermatitis and infection intertrigo).

Hands and feet:

• It is embarrassing to shake hands and it difficult to write neatly.
• Damp fingers may cause electronic equipment such as keypads and trackpads to malfunction.
• Frequent handwashing may result in dermatitis.
• Sweaty feet develop an unpleasant smell, ruin footwear and are prone to dermatitis or secondary infection tinea, impetigo or pitted keratolysis).

Treatment

General measures

• Wear loose fitting garments made of fabric that does not stain.
• Try garments that are specially designed to absorb sweat and reduce odour. Microfibre pyjamas and porous sheets may increase night-time comfort.
• Expect to change your socks several times a day. Try those scontaining silver or copper.
• Use absorbent insoles in shoes and replace them frequently.
• Don't wear the same pair of shoes two days in a row; leave them to dry out and increase their life span. Specific footwear dryers are available.
• Choose a non-soap cleanser.
• Use talcum powder or corn starch powder after bathing.
• Avoid foods and drinks that conain caffeine (coffee, tea, cola drinks, chocolate).

Antiperspirants

• Antiperspirant sprays, sticks, roll-ons, wipes and paints are available. Choose an unfragranced aluminium salt preparation suitable for hyperhidrosis (10-25% in alcohol or as a gel). Aluminium salts are sometimes combined with salicylic acid to enhance penetration.
• Antiperspirants should be applied when the skin is dry, after a cool shower just before bed. Wash off in the morning. They should be used for several consecutive nights then once or twice weekly.
• The stronger products can irritate; if so, apply hydrocortisone cream for a few days.
• Note: 'deodorants' are fragrances designed to disquise unpleasant smells, and may contain antibacterial substances. They don't affect the amount of sweat produced.
• A dusting powder containing diphemanil 2% may be useful for mild hyperhidrosis. Apply between the toes, under the breasts and other skin folds.
• Topical application of glycopyrrolate, an anticholinergic medication.