Derm Dx: Refractory dermatitis in a man on chemotherapy

Chemotherapy was initiated in a 68-year-old man with metastatic lung cancer. Several weeks after the therapy began, dermatitis developed on his scalp and cheeks, and it has not responded to topical hydrocortisone cream. The patient denies symptoms but is bothered by the appearance. Examination reveals multiple pustules and occasional crusts.