Author(s): Schallreuter KU, Tobin DJ, Panske A
BACKGROUND: It is well established that ultraviolet radiation is related to non-melanoma skin cancer (NMSC) in Caucasians. Considering that patients with vitiligo have often no protective pigment in sun-exposed depigmented/white skin together with severe oxidative stress due to accumulation of millimolar epidermal hydrogen peroxide (H(2)O(2)), it would be expected that these patients develop a higher risk for early photodamage and NMSC. However, scattered reports on low patient numbers documented no increased risk for sun-induced skin cancers in this disease. OBJECTIVE: The aim of this study was to validate the possible photodamage and the development of epidermal neoplasia in a randomly selected larger patient group with emphasis on each patient's sun sensitivity and the history of solar habits. Furthermore we wished to compare histological signs for epidermal photodamage in a random representative patient group (mean age >30 years) and age-matched healthy controls. METHODS: One hundred and thirty-six randomly selected patients (females n = 93; males n = 43; mean age 42.4 years, range 14-70 years) were included in this study. To assess signs of photodamage and skin cancer, all patients underwent a thorough full-body examination by Wood's light and dermatoscopy. In order to learn about each patient's individual sun sensitivity and solar habits, a direct questionnaire was used. In addition full skin punch biopsies of sun-exposed depigmented/pigmented skin were taken under local anaesthesia and evaluated by light microscopy. RESULTS: There was no evidence for sun-related damage in the entire patient group, despite a significant number of positive cases with a history of sunburns in early childhood and continuous accumulation of epidermal H(2)O(2). Histological examination of the epidermis showed no signs of increased photo-ageing and confirmed the absence of apoptosis in these patients. Furthermore surprisingly there was no increased risk for photosensitivity disorders, i.e. polymorphous light reaction, solar urticaria and acute actinic dermatitis. CONCLUSION: The results of this study confirm in a large group of patients with vitiligo the absence of an expected high risk for sun-induced damage and skin cancer. Based on these results together with a recent report on increased functional wild-type p53 expression in these patients we would like to propose that in vitiligo there may be a direct association between this important tumour suppressor and the absence of photodamage and NMSC.