A 9-year-old boy presented to the dermatology department with recurrent episodes of painful and pruritic vesicular lesions and erosions on his face and photoexposed areas of the arms that had occurred annually during the early summer for the preceding 3 years. These lesions developed consistently after 30 minutes of UV exposure, and all 3 previous episodes mimicked each other. Examination revealed multiple hemorrhagic crusted plaques and erosions on the face and forearms. There were also multiple varioliform scars from the previously healed lesions (Figure). Hematologic and biochemical studies, including analysis of variance and porphyrin levels, yielded unremarkable results, as did direct immunofluorescence. Skin biopsy results revealed spongiosis, focal epidermal necrosis, and intraepidermal lymphocytes. Only immunohistochemistry results for Epstein-Barr virus (EBV) latent membrane protein–1 was available, which were negative. A diagnosis of hydroa vacciniforme (HV) was made clinically, and treatment with topical corticosteroids and strict photoprotection was followed by resolution.