I imagine we’ve all been sweating a bit more than usual these past few weeks during this hot humid weather we’ve been having, but imagine being like that, only worse, all the time. Primary hyperhidrosis is probably commoner than we think, with an estimated prevalence of 1% and it can have a significant impact on an individual’s quality of life. The peak age of onset is between 15 and 18y. This useful BMJ review gives us pointers on diagnosing and managing this distressing condition (BMJ 2013;347:f6800).
First, we need to determine whether the excess sweating is primary or secondary:
Characterised by focal symmetrical sweating in a well patient affecting:
- Axillae (73%)
- Hands (46%)
- Feet (41%)
- Scalp (23%)
- Groin (9%)
- Secondary hyperhidrosis
Here, patients have generalised sweating. Consider the following causes:
- Chronic infection, e.g. TB, malaria
- Endocrine, e.g. menopause, diabetes, hyperthyroidism, acromegaly
- Drugs, e.g. alcohol, cocaine, heroin, SSRIs, acyclovir, ciprofloxacin
- Haematological malignancy
The review suggests checking FBC, U&Es, LFTs, TSH, ESR and random glucose (I would do HbA1C) to rule out secondary causes.
They also propose a set of criteria for making the diagnosis of primary hyperhidrosis: Focal, visible, excessive sweating for at least 6m without apparent cause and with at least two of the following features:
- Bilateral and relatively symmetrical
- Impairs daily activities
- At least one episode per week
- Age of onset < 25y
- Positive family history
- Cessation of focal sweating during sleep
Managing primary hyperhidrosis
- Avoid spicy food, alcohol and emotional/stressful triggers where possible.
- Use an antiperspirant rather than a deodorant.
- Wear loose-fitting clothes made from natural fibres.
Try topical aluminium chloride
- Apply at night to dry skin and rinse off in the morning, can be used with antiperspirants.
- Start with 12.5% preparation and if insufficient improvement at 6w increase to 30%.
- Skin dryness and irritation are common side-effects.
If these interventions don’t work, refer to dermatology who will consider:
- Iontophoresis: involves passing an electric current through an ion-rich medium in which the affected part of the body is placed. Patients can buy a kit and on-going weekly treatment at home is usually advised.
- Oral anticholinergics and glycopyrrolate: there are no licensed oral treatments for hyperhidrosis but dermatologists may try these drugs after appropriate discussion. There are small imperfect trials that show modest quality of life benefits but predictable significant side-effects.
- Botox: the evidence for botox is good, suggesting a 75-100% reduction in sweat, and benefits lasting for 6-9m. However, treatment is potentially lifelong and this has significant cost implications. This is not available through the NHS in most regions.
- Endoscopic thoracosympathectomy: a last resort but potentially curative procedure involving cutting the sympathetic chain as it passes through the pleural cavity. Risks include pneumothorax, persistent pleuritic chest pain and Horner’s syndrome. Patients can also get compensatory hyperhidrosis elsewhere on the body.