Hyperhidrosis — SAQ

Stem

A 17-year-old student presents with a 5-year history of bilateral, symmetric, excessive sweating of her palms and axillae. The sweating is worse during examinations and social situations, and it stops completely when she falls asleep. Her mother and maternal uncle have had similar problems. There is no weight loss, fever, night sweats, palpitations or tremor. Physical examination and vital signs are normal.

Questions

a) What is the most likely diagnosis, and what clinical features support it? (2 marks)

^[7]Primary focal hyperhidrosis (1 mark). Supporting features: bilateral and symmetric distribution, focal sites (palms and axillae), onset in childhood/adolescence (under 25 years), cessation during sleep, positive family history, and absence of systemic symptoms (1 mark).

^[6]b) Outline the first-line management for her palmar and axillary disease. (3 marks)

• Palmar disease: first-line is tap-water iontophoresis (1 mark) — direct current 15–20 mA through water for 20–30 minutes, 3–4 times per week initially, then weekly maintenance.
• Axillary disease: first-line is topical aluminium chloride hexahydrate 20% (1 mark) — applied at night to completely dry skin, washed off in the morning, nightly for 3–7 days then maintenance once or twice weekly.
• General measures: avoid triggers (heat, stress, spicy foods), absorbent clothing, regular skin care, and reassurance about the benign nature of the condition (1 mark).

^[5]c) If her axillary hyperhidrosis fails to respond to topical therapy, what is the next step, and what are the mechanism and duration of effect? (2 marks)

^[4]- Next step: intradermal botulinum toxin A injections into the axillae (1 mark), typically 50–100 units per axilla in a grid pattern.

• Mechanism: botulinum toxin blocks the calcium-dependent release of acetylcholine from cholinergic sympathetic nerve terminals, preventing eccrine gland stimulation (0.5 mark).
• Duration: effect lasts approximately 4–9 months, commonly 6 months (0.5 mark).

^[3]d) What is the most important complication to discuss if endoscopic thoracic sympathectomy (ETS) is being considered for severe palmar disease, and why is ETS reserved for refractory cases? (2 marks)

• Compensatory hyperhidrosis is the most important complication, occurring in 50–90% of patients (1 mark). It produces new excessive sweating on the trunk, back, groin or thighs and can be more disabling than the original palmar disease; it is often irreversible.
• ETS is a last resort because of this unpredictable and potentially severe complication, and because less invasive treatments (iontophoresis, botulinum toxin) are usually effective (1 mark).

^[2]e) What features in the history would suggest a secondary cause rather than primary focal hyperhidrosis? (1 mark)

^[1]Generalised rather than focal sweating, onset after age 25, sweating that persists during sleep or occurs as night sweats, asymmetric or unilateral distribution, and associated systemic symptoms such as fever, weight loss, palpitations, tremor, heat intolerance or neurological signs.

References7ShowHide

1. [1]Pariser DM, Krishnaraja J, Tremblay TM, et al. Randomized, placebo- and active-controlled crossover study of the safety and efficacy of THVD-102, a fixed-dose combination of oxybutynin and pilocarpine, in subjects with primary focal hyperhidrosis J Drugs Dermatol, 2017.PMID 28300854
2. [2]Saadia D, Voustianiouk A, Wang AK, et al. Botulinum toxin type A in primary palmar hyperhidrosis: randomized, single-blind, two-dose study Neurology, 2001.PMID 11739832
3. [3]Lowe NJ, Glaser DA, Eadie N, et al. Botulinum toxin type A in the treatment of primary axillary hyperhidrosis: a 52-week multicenter double-blind, randomized, placebo-controlled study of efficacy and safety J Am Acad Dermatol, 2007.PMID 17306417
4. [4]Kim J, Han N, Koo H, et al. Efficacy and Safety of Topical Anticholinergics in the Treatment of Primary Axillary Hyperhidrosis: A Systematic Review and Meta-analysis Clin Drug Investig, 2026.PMID 41989535
5. [5]Kim J, Han N, Koo H, et al. Efficacy and Safety of Topical Anticholinergics in the Treatment of Primary Axillary Hyperhidrosis: A Systematic Review and Meta-analysis Clin Drug Investig, 2026.PMID 41989535
6. [6]Pariser DM, Krishnaraja J, Tremblay TM, et al. Randomized, placebo- and active-controlled crossover study of the safety and efficacy of THVD-102, a fixed-dose combination of oxybutynin and pilocarpine, in subjects with primary focal hyperhidrosis J Drugs Dermatol, 2017.PMID 28300854
7. [7]Nawrocki S, Cha J. The etiology, diagnosis, and management of hyperhidrosis: A comprehensive review: Etiology and clinical work-up J Am Acad Dermatol, 2019.PMID 30710604