Xylazine-Induced Necrotic Skin Ulcers in a Fentanyl-Injecting Individual in South Florida, United States: A Case Report

Xylazine, commonly referred to as "Tranq," is an alpha-2-adrenergic receptor agonist that is FDA-approved only as a sedative and tranquilizer for veterinary use. However, its use as an adulterant in various illicit drugs, including fentanyl, has been on the rise, leading to its street name, "Tranq-Dope." Intravenous injection use of xylazine produces distinctive skin ulceration with accompanying necrosis, which can be considered virtually pathognomonic. A 41-year-old male with polysubstance abuse disorder presented to the emergency department with severe skin ulcerations on the right forearm and left calf with associated pain and erythema at injection sites. The concern for complicated skin tissue infection was acknowledged and the patient was admitted. The initial urine toxicology report was positive for cocaine, cannabinoids, benzodiazepines, and fentanyl. Upon detailed history-taking, the patient attested to recent changes in the sedative and euphoric effects of fentanyl use, which increased the index of suspicion for xylazine exposure. Immunoassay-based xylazine test strips were positive. Initially, he was administered broad-spectrum intravenous antibiotics, then switched to oral antibiotics at discharge. He was compliant with starting buprenorphine and buprenorphine-naloxone following discharge for management of his severe opioid use disorder. Xylazine's alpha-2-adrenergic agonistic properties in the periphery are thought to initiate a cascade of effects starting with vasoconstriction causing impaired blood perfusion hindering wound healing and increasing vulnerability to secondary infections. This case report aims to alert the medical community about the alarming occurrence of xylazine as an adulterant in illicit drugs and to describe the characteristic skin lesions associated with xylazine injections. Awareness of xylazine use should be considered in patients who develop necrotic skin ulcerations at injection sites along with alterations in typical effects of drug use.