Hyperhidrosis (Excessive Sweating)

Hyperhidrosis is classified as primary focal (idiopathic, symmetric, family history common, beginning before age 25, sparing during sleep) or secondary generalized (related to endocrine, neurologic, infectious, malignant, or drug-induced causes). Primary focal disease typically affects the axillae, palms, soles, craniofacial region, or combinations and is mediated by overactive cholinergic sympathetic innervation of eccrine glands rather than gland number or size.

Diagnostic criteria require focal visible sweating for at least 6 months without apparent cause plus two of: bilateral and symmetric distribution, frequency >1 episode per week, age of onset <25 years, family history, impairment of daily activities, and cessation during sleep. Severity is graded with the Hyperhidrosis Disease Severity Scale (HDSS); evaluation excludes thyrotoxicosis, pheochromocytoma, lymphoma, tuberculosis, and medications such as SSRIs.

Stepwise treatment begins with aluminum chloride hexahydrate antiperspirants and glycopyrronium tosylate cloth for axillae. Iontophoresis is effective for palms and soles. Onabotulinum toxin A injection (50 U/axilla, 100 U/palm) provides 4-7 months of relief. Oral anticholinergics (oxybutynin, glycopyrrolate) and clonidine treat generalized cases but cause dry mouth. Microwave thermolysis (miraDry) provides durable axillary reduction. Endoscopic thoracic sympathectomy (T3-T4) is reserved for severe palmar disease but causes compensatory sweating in many patients.