Pityriasis rosea-like drug reaction to asenapine

Pityriasis rosea (PR) is a relatively common, benign skin disease of unknown etiology. In rare cases, medications can induce a morphologically similar eruption. We present a case of a PR-like drug eruption caused by the atypical antipsychotic asenapine. The clinical presentation consisted of a rapidly progressive, disseminated, and severely pruritic dermatitis comprised of ovoid, scaly, pink-violaceous plaques. The initial histopathologic specimen was consistent with PR, but upon re-sampling a week later, the findings favored a drug eruption. PR-like drug eruptions, though rare, can occur in response to a wide variety of medications. Because the findings may be only subtly different than those of typical PR, careful clinical and histopathological correlation must be sought. To our knowledge, this is the first reported case of a PR-like drug eruption to asenapine.