Acyclovir-induced Fixed Drug Eruption in a 17-year-old Female Aided by Dermoscopy: Cross-reactivity and Treatment Considerations

Fixed drug eruption (FDE) is a cutaneous reaction characterized by erythematous plaques that recur at the same site on reexposure to the triggering drug. Acyclovir, a commonly used antiviral agent, has been rarely implicated in FDE. It is usually prescribed in the treatment of herpes labialis. We report a case of a 17-year-old female who developed FDE after 5 days of acyclovir therapy. This report also explores cross-reactions with famciclovir and valacyclovir, treatment options for recurrent episodes, and the challenges of drug hypersensitivity testing.