Abstract

Xylazine is a veterinary tranquilizer and an increasingly prevalent fentanyl and heroin adulterant in the United States that potentiates their opioid effects. Apart from its systemic depressive properties leading to opioid overdose, cutaneous xylazine toxicity is also recognized. While the pathophysiology of xylazine-induced skin ulceration is not fully understood, tissue ischemia is postulated to occur as a result of direct vasoconstriction. Nonetheless, sites of involvement both local to and distant from injection are reported. Herein, we present a case of xylazine-induced skin ulceration in a 59-year-old man with clinical evolution and pathologic correlation. The patient presented to the emergency department with left forearm pain and swelling several days after intravenous injection of heroin. Urine drug screen was positive for fentanyl. Physical exam was initially notable for ill-defined purpuric plaques overlying dusky erythema and induration of the left forearm, which quickly progressed to frank necrosis and ulceration. The patient continued to worsen over one week despite treatment with broad-spectrum antibiotics for suspected cellulitis, and Dermatology was consulted. Skin biopsy was performed and revealed complete epidermal necrosis, ulceration, and superficial and deep dermal neutrophilic inflammation without vasculitis. Interestingly, diffuse eccrine gland necrosis was also noted. Given the association of eccrine gland necrosis with other cutaneous manifestations of drug toxicities (i.e. barbiturates, benzodiazepines, etc.), this histologic finding may be a diagnostic clue for xylazine-induced skin ulceration in the appropriate clinical context. However, further studies are needed to fully define the histopathologic spectrum of this newly described cutaneous entity with growing public health concern.