Botulinum Toxin Therapy in Hidradenitis Suppurativa

Inclusion: * Adults between ages 18 and 75 years with established diagnosis of hidradenitis suppurativa (HS) * HS skin lesions of duration at least 1 year, HS skin lesions in at least two different body areas Exclusion: * Age \< 18 years or \> 75 years * pregnant or breastfeeding * neuromuscular disorder (ex. ALS, myasthenia gravis, Lambert-Eaton syndrome, myopathy) * medical co-morbidity that is a relative contraindication to skin biopsy procedure (ex. end stage congestive heart failure or coagulopathy) * active bacterial, fungal, or viral infection in the treatment area * known hypersensitivity to botulinum toxin A preparations or any of their components (human albumin, saline, lactose, sodium succinate) * prisoners * adults unable to consent for themselves.