Objective assessment of photoageing effects using high-frequency ultrasound in PUVA-treated psoriasis patients.

Abstract

Skin ageing can be differentiated into intrinsic (chronological) ageing, and photoageing due to chronic sun exposure. Photoageing is the superimposition of photodamage on the ageing process. The aim of the study was to investigate possible differences between the skin of photochemotherapy (PUVA)-treated psoriasis patients and of untreated normal subjects using a high-frequency ultrasound system. A total of 124 volunteers (aged 21-88 years, median 52 years, 62 female, 62 male), 62 psoriasis patients who had received PUVA therapy and 62 healthy controls, were investigated. Skin thickness and a subepidermal low-echogenic band (SLEB), a parameter for photodamage, were measured in 12 different areas. Female skin is thinner than male skin. The skin thickness values of PUVA patients were more markedly decreased than those of the controls for the older patients. There was a clear dependence of the occurrence of SLEB on PUVA therapy in psoriasis patients. Long-term PUVA treatment in psoriasis patients accelerates thinning of the skin in comparison to age-matched controls. The results show that ultrasonography is a sensitive method to investigate the effects of PUVA-induced skin ageing.