Abstract
A 71-year-old woman with a history of multiple squamous cell carcinomas and pancreatic cancer metastatic to the liver on chemotherapy presented to clinic with an itchy rash. On exam, she had erythematous scaly papules and purpuric macules on the arms and legs. Chemotherapy regiment included gemcitabine, paclitaxel and batiraxcept. Biopsy of one of the lesions revealed a superficial lymphocytic infiltrate with partial to nearly full thickness keratinocyte atypia and solar elastosis consistent with actinic keratoses. Purpuric eruptions in the setting of chemotherapy bring up a broad differential diagnosis with many concerning possibilities. Hematogenous spread of fungal organisms, drug induced vasculitis, purpura fulminans and other entities need to be considered. Chemotherapeutic agents can also lead to inflammation of pre-existing actinic keratoses. Lesions are often subclinical and limited to sun-exposed areas. In a setting of low platelet counts, inflamed keratoses may appear purpuric. Chemotherapy-induced inflammation of actinic keratoses have been described in patients receiving 5-fluoruracil, capecitabine, doxorubicin, cytarabine and sorafenib among others. It is important to recognize this phenomenon as lesions can be managed successfully with topical steroids thus avoiding the need to discontinue chemotherapy. The medicines and pathogenesis of this interesting reaction pattern will be reviewed.