Sunlight Avoidance and Cancer Prevention in Xeroderma Pigmentosum

Xeroderma pigmentosum (XP), a rare autosomal recessive disease, has dramatic sun sensitivity and median skin cancer onset at 8 years of age. The risk for cutaneous neoplasia is at least 1000 times that of the general population. While all experts recommend strict sun protection and avoidance for XP patients, few data exist on the efficacy of these preventive measures. We describe three patients who, after adhering to strict protocols for UV light avoidance and shielding, lack the level of dermatologic injury often found in persons with XP at corresponding ages (Figure). REPORT OF CASES.CASE 1. A girl (XP104SF) born of nonconsanguineous parents on December 13,1979, had bright erythema persisting 2 days after a carriage ride at age 3 months. Subsequent episodes followed 15-minute sun exposures. Despite shaded exposure and sun protection factor-15 sunscreen use, second-degree sunburns followed. While physicians initially suspected child abuse, subsequent phototesting showed striking sensitivity, and