Trips Through the Skin: Reviewing Cutaneous Drug Reactions to Psychedelics and Hallucinogens.

Although psychedelic and hallucinogenic substances have gained popularity for therapeutic use, their dermatologic adverse effects are poorly characterized. This review characterizes the cutaneous reactions associated with psychedelic and hallucinogenic drugs. A review of PubMed and Scopus was conducted from the inception of databases to August 31, 2023. Search terms included drug names and classes (cannabis, MDMA, ecstasy, 3,4-methylenedioxymethamphetamine, psychedelics, hallucinogens, peyote, marijuana, lysergic acid diethylamide, LSD, ketamine, dimethyltryptamine, DMT, phencyclidine, PCP, dextromethorphan, psilocybin, and ayahuasca), and dermatosis terms (dermatitis, contact dermatitis, drug eruption, skin reaction, and urticaria). Studies were included if there was an association with a psychedelic or hallucinogenic and any cutaneous reaction; studies without both components were excluded. Twenty-two studies met inclusion criteria, describing reactions to cannabis (10 studies), MDMA (5 studies), ketamine (4 studies), and psilocybin (3 studies). Forty total patients were included. Among cannabis-related reactions, the most common reaction was type I hypersensitivity by topical exposure (n = 21). Three patients reported type IV hypersensitivity reactions to contact with cannabis or cannabis-derived oils, all of whom experienced vesicular contact dermatitis. Two additional patients presented with an erythema-multiforme-like reaction and acute generalized exanthematous pustulosis after systemic administration, respectively. MDMA was associated with acneiform eruptions (2 cases), an urticarial eruption, a guttate psoriasis-like reaction, a fixed drug eruption, and Stevens-Johnson syndrome (1 case). Four patients reported type I hypersensitivity reactions to ketamine. Four patients reported vesicular eruptions, cyanosis, or widespread jaundice to psilocybin. Of the cases, 8 patients had cutaneous reactions that resolved with drug cessation, 10 resolved with cessation plus treatment, and resolution in 7 cases was not reported. Zero studies were found describing other psychedelic or hallucinogenic compounds. Further research is required to characterize reactions and treatments linked to the variety of extant psychedelics and hallucinogens.