Hyperhidrosis

Hyperhidrosis is a condition where inappropriate excessive sweating occurs. It may be focal (affecting axillae, palms, soles or scalp) or generalised.¹ Common triggers include emotion, intense concentration and spicy foods.

• Focal hyperhidrosis is much more common. There is usually no identifiable cause but it often runs in families.
• Generalised hyperhidrosis is usually associated with an underlying cause.

• Anxiety
• Heart failure, myocardial ischaemia
• Compensatory hyperhidrosis: injury to the sympathetic trunk (including after endoscopic thoracic sympathectomy)² or diabetic neuropathy may lead to an area of the body with absence of sweating, which then leads to an area of compensatory hyperhidrosis in another part of the body
• Drug adverse effect, e.g. aspirin, paracetamol, fluoxetine
• Hyperthyroidism, diabetes mellitus (hypoglycaemia, autonomic neuropathy), acromegaly, phaeochromocytoma, hypothalamic lesions
• Infection
• Inherited causes are rare but include familial dysautonomia and nail-patella syndrome
• Malignancy: especially lymphoma, intrathoracic malignancy, carcinoid tumour
• Respiratory failure

• Focal hyperhidrosis is relatively common with an estimated prevalence of 1-3%.
• Prevalence is difficult to estimate as many people do not seek professional help.
• Focal hyperhidrosis usually starts at puberty, but can present at any age. Palmar and plantar hyperhidrosis may be present at birth.

Assessment is focused on establishing or elimination an underlying cause.

Typical focal hyperhidrosis often requires no further investigation. Any initial investigations will often depend on individual context of patient and the history and examination but often include:

• Full blood count
• ESR and/or CRP
• Urea and electrolytes
• Liver function tests
• Fasting blood glucose
• Thyroid function tests
• Chest X-ray
• Further investigations will also depend on individual circumstance, e.g. HIV testing

Generalised hyperhidrosis

Usually due to an underlying disorder and management is directed at finding and treating any underlying cause, which usually includes specialist referral.

Primary focal hyperhidrosis

• General advice:¹
  • Avoid clothes that show sweat marks readily (white or black are suitable colours). Wear loose-fitting clothing. Avoid man-made fibres, e.g. nylon.
  • Soap substitutes reduce skin irritation.
  • Avoid any obvious trigger factors
  • Frequently change clothing, including shoes to allow them to dry properly, and avoid heavy occlusive footwear such as boots or sports shoes
• Further treatments:
  • Topical aluminium salt antiperspirants can be used on the axillae, feet, and hands but are not recommended for use on the face, where the skin is sensitive.
  • If treatment with a topical aluminium salt fails, consider referral for further assessment and consideration of other treatments.
  • Iontophoresis:
    • In more severe cases, glycopyrronium bromide as a 0.05% solution is used in the iontophoretic treatment of hyperhidrosis of plantar and palmar areas.
    • Iontophoresis can also be used to treat axillary hyperhidrosis.
    • Some people seem to gain considerable symptom relief.
    • Treatment usually consists of 3-4 treatment sessions per week. Each treatment session lasts 20-30 minutes. Multiple treatments are usually required. Most people report an improvement after 6-10 sessions. Maintenance treatment is typically required at 1-4-week intervals.¹
  • Botulinum type A toxin:
    • Botulinum A toxin-haemagglutinin complex is licensed for use intradermally for severe hyperhidrosis of the axillae unresponsive to topical antiperspirant or other antihidrotic treatment.
    • It is given by repeated intradermal injections into the affected area.
    • It has been shown to be safe and effective.³
• Surgery:
  • Usually only considered if other treatment options have failed or have not been tolerated:
  • Subcutaneous sweat gland curettage of the axillae.
  • Subcutaneous curettage is very effective and has fewer potential side-effects than sympathectomy.⁴
  • Complications of local axillary surgery include haematoma, scarring, and wound infections.
  • Sympathectomy:
    • Usually carried out endoscopically via the transthoracic route.⁵
    • Compensatory hyperhidrosis is the most common adverse effect and causes sweating in such areas as the chest, back, thighs and groin and can be extremely disabling.
    • Other complications include pneumothorax, Horner's syndrome, brachial plexus injuries, post-operative neuralgia, and recurrent laryngeal nerve palsy.¹

• Severe hyperhidrosis can cause extreme embarrassment that may lead to social and professional isolation⁵
• Secondary infections
• Dermatitis

• Primary focal hyperhidrosis usually runs a chronic course, although a small number of people spontaneously improve after the age of about 25 years.¹