Topical Imiquimod: Be Aware of the Unexpected

The document reports a rare but serious side effect of imiquimod, a drug commonly used for superficial basal cell carcinomas (SBCCs). An elderly woman developed atypical targetoid lesions and symptoms consistent with toxic epidermal necrolysis/Stevens-Johnson syndrome (TEN/SJS) after using imiquimod. Despite negative initial tests, the timeline of events and continuous application of imiquimod suggested it as the trigger. The case emphasizes the importance of being aware of potential serious adverse reactions of medications, the necessity of informed consent, and the value of diligent adverse event reporting. The document also highlights that current laboratory testing cannot replace a thorough history and timeline in the case of suspected drug eruptions. The patient recovered fully after the withdrawal of imiquimod and intensive skin care. This case aims to raise awareness among healthcare professionals about the need to consider and inform patients of the rare but severe side effects of imiquimod.