Hydroa vacciniforme.

The article presents a reprint of the article "Hydroa vacciniforme," by Dr. Riccardo Balestri and Dr. Iria Neri, which appeared in www.cmaj.ca. It presents the case of a 10-year-old boy who had repeated lesions for three years. It states that initial differential diagnosis include lupus erythematosus, actinic prurigo, and hydroa vacciniforme. The patient was diagnosed with hydroa vacciniforme, an idiopathic photodermatosis, via histologic examination and a provocation test for ultraviolet A.