Suspected Xylazine-Associated Skin Ulcers in Montreal, Canada: A Case Report on Diagnostic Challenges and Multidisciplinary Care.

Xylazine is a non-opioid α2-adrenergic receptor agonist originally synthesized as an antihypertensive but repurposed for veterinary sedation due to severe central nervous system side effects. In recent years, xylazine has increasingly entered the North American illicit drug supply, frequently adulterating stimulants and opioids to prolong and intensify their psychoactive effects. Its potent α2-adrenergic agonist activity has been proposed to contribute to localized skin ischemia and necrotic wound development via peripheral vasoconstriction, though the exact pathogenesis remains incompletely understood and is likely multifactorial. This report documents what is, to our knowledge, the first reported Canadian case of suspected xylazine-associated skin ulceration in the peer-reviewed literature. We present the case of a 64-year-old male with a history of polysubstance use who was admitted to a tertiary care hospital in Montreal, Quebec, on two separate occasions with severe, treatment-resistant necrotic ulcerations across his extremities. Standard therapeutic interventions, including multiple antibiotic courses and surgical debridement, yielded no clinical improvement. Consultation-liaison psychiatry evaluation uncovered that the patient was actively using illicit cocaine during his hospitalization, raising clinical suspicion for xylazine contamination of his drug supply. Confirmatory xylazine testing was not available within the relevant detection window; accordingly, the diagnosis is clinical and presumptive, based on characteristic wound features, temporal association with use of an illicit drug supply known to contain xylazine, and exclusion of alternative etiologies. Following targeted psychoeducation, substance cessation, and a multidisciplinary wound management strategy, the patient's wound progression halted and significant healing was observed. This case highlights critical diagnostic and public health challenges, including limited clinician familiarity with xylazine-associated wounds, insufficient rapid screening infrastructure, and the absence of standardized clinical management guidelines in Canada. Frontline healthcare providers should maintain a high index of suspicion for xylazine exposure when evaluating non-healing, progressive necrotic lesions in individuals who use illicit substances.