Actinic damage among patients with psoriasis treated by climatotherapy at the Dead Sea.

BACKGROUND: Dead Sea climatotherapy is highly effective in the treatment of psoriasis. However, its potential side effects, especially the risk of skin cancer, are unclear. OBJECTIVE: We sought to determine the prevalence of solar damage and skin cancer among patients with psoriasis who underwent Dead Sea climatotherapy compared with control patients. METHODS: This multicenter controlled cross-sectional study was carried out at the Dead Sea Solarium Clinic and outpatient clinics of the participating centers. A total of 1198 participants (460 patients with psoriasis and 738 control patients) aged 20 to 70 years were included. A standard questionnaire including demographic parameters and sun exposure habits was administered to all participants. Patients were questioned about previous psoriatic treatments and climatotherapy at the Dead Sea. All participants underwent a structured physical examination of the skin. We compared the prevalence of solar damage for patients with psoriasis and control patients and assessed the extent of photodamage among patients with psoriasis according to exposure time at the Dead Sea in univariate and multivariate analyses. RESULTS: Elastosis ( P < .001), solar lentigines (P = .03), poikiloderma (P < .001), and facial wrinkles (P < .001) were significantly more common among patients with psoriasis compared with control patients and showed a dose response with increased Dead Sea exposure time. Self-reported previous skin cancers were more common in control patients compared with patients with psoriasis (8.2% vs 3.5%, P = .002), however, the prevalence of nonmelanoma skin cancer on examination did not differ between the two groups. No cases of malignant melanoma were detected in either group. CONCLUSIONS: Dead Sea climatotherapy is not associated with an increased risk of malignant melanoma or nonmelanoma skin cancer for patients with psoriasis in Israel. However, UV exposure at the Dead Sea may play a role in the development of solar damage.

Are patients with psoriasis susceptible to the classic risk factors for actinic keratoses?

BACKGROUND: An increased prevalence of benign solar damage (eg, facial wrinkles) but not neoplastic lesions was observed among patients with psoriasis who were exposed to Dead Sea climatotherapy compared with controls. OBJECTIVES: To compare the prevalence of actinic keratosis in psoriatic patients and controls and to assess whether known risk factors behave similarly in both groups. DESIGN: Multicenter cross-sectional study. SETTING: Dermatology clinics in 4 participating Israeli hospitals and at a Dead Sea clinic. PARTICIPANTS: Adult subjects (n = 460) with plaque-type psoriasis were recruited from the Israel Psoriasis Association (volunteer sample) and from dermatology clinics (convenience sample). The control group (n = 738) consisted of nonimmunosuppressed patients attending these clinics for benign conditions unrelated to sun exposure, such as atopic or contact dermatitis. MAIN OUTCOME MEASURES: Prevalence and distribution of actinic keratoses and odds ratios associated with skin, hair, and eye color and propensity or history of sunburn adjusted for age, ethnicity, and sun exposure. RESULTS: Actinic keratoses were observed in 200 controls (27%) and 51 subjects (11%) (P<.001). This increased prevalence occurred in both sexes, participants aged 35 years or older, all ethnic groups, smokers, and nonsmokers. The anatomical distribution of lesions did not substantially differ between subjects and controls. In multivariate analysis, psoriasis conferred a protective effect (odds ratio, <1), as did dark skin, dark eyes, and a history of severe sunburn in childhood. However, significant interactions were observed between psoriasis and hair color as well as psoriasis and propensity to sunburn, whereby a linear association was observed for controls but not for patients with psoriasis. CONCLUSIONS: Psoriasis confers protection against actinic keratosis. Hair color and propensity to sunburn exert differential effects among psoriatic patients and controls.