Table 8. Cannabinoids and adverse cutaneous events.

CBD, cannabidiol.

Adverse event	Comment	Reference
Acne, hair loss, and premature aging	Among 136 patients being treated for addiction to synthetic cannabinoids, the most common dermatologic findings were acne, grey hair, hair loss, hallowed cheeks, periorbital darkening, and premature aging	[10]
Acute generalized exanthematous pustulosis	Acute generalized exanthematous pustulosis is a type IV hypersensitivity reaction that manifests as an acute rash within 48 hours of being exposed to certain drugs, including antibiotics, antifungals, CBD, and cocaine	[11]
Allergic contact dermatitis	Several studies have demonstrated allergic contact dermatitis to cannabinoids. A study of 129 people showed 63 individuals to have a positive skin test for marijuana pollen. Another study found that 78 of 127 patients tested (61%) had a positive skin test for cannabis pollen. The specific mechanism of action has not been fully elucidated, but an in vitro study found that cannabinoid receptor 2 can mediate the ability of dendritic cells to induce hapten-induced contact hypersensitivity in mice, which is an established animal model for allergic contact dermatitis	[12,13]
Contact urticaria	A 29-year-old technician developed wheals, rhinitis, and headaches after two years of occupational exposure at Forensic Science Service. Patch testing yielded a positive result for cannabis leaf	[14]
Eczema herpeticum	Cannabinoid abuse may be an underestimated risk factor for triggering eczema herpeticum in patients with atopic dermatitis or Darier disease. Eczema herpeticum is caused by the reactivation of the latent herpes simplex virus	[15]
Erythema ab igne	Erythema ab igne is triggered by excessive heat exposure from heating devices, heating pads, or laptop use. It can also be seen as a complication of cannabis hyperemesis syndrome	[16]