An 80-year-old white woman presented to our dermatology clinic with a rash across her abdomen that had been there for more than a year. While not itchy or painful, the rash was slowly expanding. The patient had tried treatments including topical antifungals and topical corticosteroids, but none had helped.
Her medical history was significant for dementia and stage III triple-negative breast cancer in the left breast (diagnosed 8 years prior), which was treated with a simple left mastectomy, chemotherapy, and radiation. She reported no history of skin cancer. She was not taking any medications and had no known drug allergies. A physical examination revealed an erythematous, papulonodular rash with diffuse induration in a band-like pattern across her entire upper abdomen and left flank (FIGURE).