Localized Hyperhidrosis: Focal Excessive Sweating Causes and Treatments

Definition

Primary focal hyperhidrosis: Excessive sweating in specific areas (palms, soles, axillae, face, scalp, groin) unrelated to thermoregulation, typically bilateral and symmetric, onset <25 years, not during sleep.

Pathophysiology

• Overactive sympathetic cholinergic sudomotor output.
• Genetic predisposition (autosomal dominant with variable penetrance).
• Triggered by emotional stress, heat, spices—not core temperature.

Common Sites

• Palmar (hands): Impairs grip, paper handling, social interaction.
• Plantar (feet): Maceration, infections, footwear damage.
• Axillary: Visible staining, odor, clothing damage.
• Craniofacial: Social embarrassment, makeup disruption.

Treatment Ladder

1. Topical aluminum chloride (20–25%): Nightly application; first-line for axillae, palms, soles.
2. Iontophoresis: Tap water baths with electrical current; 3–4x/week initially; high success for palms/soles.
3. Oral anticholinergics: Glycopyrrolate, oxybutynin; systemic side effects (dry mouth, constipation, urinary retention).
4. Botulinum toxin A: Intradermal injections; 4–6 month duration; FDA-approved for axillae; off-label for palms/soles.
5. Microwave thermolysis (miraDry): Permanent axillary sweat gland destruction.
6. Endoscopic thoracic sympathectomy (ETS): Last resort; risk of compensatory hyperhidrosis (50–90%).

Secondary hyperhidrosis (generalized, onset >25, nocturnal) requires investigation for underlying cause (endocrine, neurologic, malignancy, medication).