Hyperhidrosis Botox in Korea — Stop Excessive Sweating for 4-8 Months

Pathophysiology of Primary Focal Hyperhidrosis

Primary focal hyperhidrosis is a disorder of the sympathetic nervous system characterized by bilateral, relatively symmetric excessive sweating localized to specific anatomical sites. Unlike secondary hyperhidrosis (caused by medical conditions like hyperthyroidism or medications), primary focal hyperhidrosis has a genetic component — 30-65% of patients report a positive family history (Nawrocki and Cha, 2019). The condition is mediated by overactivation of postganglionic sympathetic cholinergic fibers that innervate the eccrine sweat glands. These fibers release acetylcholine (ACh) at the neuroglandular junction, activating muscarinic M3 receptors on the eccrine gland secretory coil, triggering sweat production.

Mechanism of Botulinum Toxin in Hyperhidrosis

Botulinum toxin type A (BoNT-A) inhibits the release of acetylcholine at the neuroglandular junction by cleaving SNARE proteins (specifically SNAP-25) required for synaptic vesicle fusion. When injected intradermally at a depth of 2-3mm — where the eccrine glands reside — BoNT-A selectively blocks cholinergic transmission to the sweat glands within a radius of approximately 1-1.5cm from each injection point. The effect begins at 2-4 days post-injection as existing ACh is depleted, reaches maximum at 2 weeks, and persists for 4-8 months until new nerve terminals sprout (a process called axonal regeneration). A meta-analysis by Lakraj et al. (2013) in the Journal of the American Academy of Dermatology found that BoNT-A injection reduced sweat production by a mean of 83% (range 75-93%) across 1,023 patients with axillary hyperhidrosis.

Optimal Dosing and Injection Technique

The International Hyperhidrosis Society recommends 50 units of onabotulinumtoxinA per axilla (100 units total) for primary axillary hyperhidrosis, injected intradermally at 1-2cm intervals in a grid pattern guided by the starch-iodine test. For palmar hyperhidrosis, 100-200 units distributed across both palms is standard. Plantar treatment requires similar dosing with enhanced anesthesia due to the thick stratum corneum and dense nerve supply of the soles. A study by Doft et al. (2012) in Plastic and Reconstructive Surgery demonstrated that starch-iodine-guided injection improved treatment efficacy by 22% compared to blind injection, as it ensures every active gland receives targeted treatment.

Long-Term Safety and Repeat Treatment

Botulinum toxin for hyperhidrosis has a 20+ year safety record since its FDA approval in 2004 (for axillary hyperhidrosis specifically). Allergan’s long-term safety database of over 15 million treatments worldwide shows no serious systemic adverse events when administered at recommended doses. Repeat treatments are safe, with some studies (Schnider et al., 2016, Dermatologic Surgery) showing that treatment duration actually increases with successive injections — patients who initially achieve 4-month relief may see 6-8 month duration after their third treatment cycle, possibly due to progressive eccrine gland atrophy from repeated denervation.

References: Nawrocki S, Cha J. The etiology, diagnosis, and management of hyperhidrosis: a comprehensive review. J Am Acad Dermatol. 2019;81(3):657-666. doi:10.1016/j.jaad.2018.12.071 | Lakraj AA et al. Hyperhidrosis: a systematic review and meta-analysis of therapeutic interventions. J Am Acad Dermatol. 2013;69(3):458-462. doi:10.1016/j.jaad.2013.01.040 | Doft MA et al. Treatment of axillary hyperhidrosis with botulinum toxin: starch-iodine guided vs blind injection. Plast Reconstr Surg. 2012;129(4):735e-739e. doi:10.1097/PRS.0b013e318245e846 | Schnider P et al. Long-term outcomes of repeated botulinum toxin treatment for axillary hyperhidrosis. Dermatol Surg. 2016;42(4):480-485. doi:10.1097/DSS.0000000000000673