Search

Skin fibroblasts from a patient with the photosensitive disorder hydroa vacciniforme were tested in vitro for DNA repair capacity. The rate of ultraviolet light (254 nm)-induced unscheduled DNA synthesis (UDS) in these fibroblasts was found to be 51-59% of the rate found in 4 normal fibroblasts strains. The patient had none of the clinical signs of the classic DNA deficient disease, xeroderma pigmentosum.

Hydroa vacciniforme is a rare photosensitivity disorder with onset in childhood. The distinctive lesion is a vesicle which heals with scarring. We report a case of hydroa vacciniforme in which an abnormal minimal erythema dose to wavelengths of 322 to 370 nm within the ultraviolet A (UVA) range was demonstrated. Vesicles could be induced only with multiple exposures to UVA. Increased tolerance to UVA erythema was induced by multiple UVB exposures, although tanning was poor. Of note were the presence of several halo nevi and a history of the loss of ability to tan. The clinical features and appropriate laboratory evaluation of hydroa vacciniforme are reviewed.