29th Annual Meeting of the American Society of Photobiology

Downtown Marriot

Chicago, Il.

Skin Type Prevalence and Significance in Ireland.

Abstract-
In a survey of 400 hospital patients which included orthopaedic and dermatology patients, the following prevalence of skin types was noted using the Fitzpatrick Classification: 26% skin type I, 50% skin Type II, 24% were skin type III, no skin type IV or higher were identified, reflecting the skewing of the Irish population towards the fairest of skin types. No difference in distribution of skin type was detected between dermatology and orthopaedic patients, implying that the survey was representative of the general population, In the last two years, we have surveyed the skin type of 200 patients with non-melanoma skin cancers (NMSC). All patients with squamous cell carcinomas were either skin type I or II, by contrast patients with basal cell carcinomas (BCCs) comprised 19% skin type I, 51% skin type II and 29% skin type III reflecting skin types found in the general population. Using high resolution ultrasound we found that patients with SCCs were more likely to have severe solar damage as documented by the presence of the sub-epidermal echo-lucent band compared with controls. Patients with BCCs (n=119) had only moderate amounts of solar damage, and patients with malignant melanoma (N=100) often had little evidence on ultrasound of solar damage, the notable exception being those with lentigo maligna melanoma or those presenting in the 6-7th decade. Using the Reflectance meter (Diastron) we found that constitutive skin colour was a more accurate predictor of minimal erythema dose (MED) of Solar Simulated Radiation (SSR) compared with the Fitzpatrick method in skin types I-VI. Basal cell carcinoma patients (Skin types I and II) however were found to produce a pattern of apoptosis after 3MEDs which differed from a skin type and MED matched set of controls, implying that DNA damage limitation mechanisms are impaired in patients with BCCs. The rates of skin cancers in Ireland are exceedingly high given the northern latitude of the country. The cumulative risk of NMSC is 18.4% by age 75 years for men, and the rate of malignant melanoma is 16.7/100,000 population, representing the 3rd highest rate in Europe. Objective documentation of solar damage helps target educational messages to those at particular risk and gives information on cumulative exposure of the population.

Keywords: phototype, cancer, ultraviolet, sun