Dysfunction of epidermal barrier in psoriasis

Objective To seek experimental evidence of epidermal barrier dysfunction in psoriasis,and to provide a basis for adjuvant therapy of psoriasis.Methods Physiometric methods were used to determine the value of sebum content,transepidermal water loss (TEWL) and water content of stratum corneum in 60 patients with psoriasis and 48 normal human controls.The ultrastructure of lamellar bodies was observed with transmission electron microscopy,and the expression of acid ceramidase in normal skin and psoriatic lesions was detected by using immunohistochemical techniques.Results Compared with the normal skin,TEWL value was increased (P ＜ 0.01),but water content of stratum corneum decreased (P ＜ 0.01 ) in psoriatic lesions,and sebum content was similar between normal skin and psoriatic lesions.As electron microscopy showed,lamellar bodies in keratinocytes were reduced in number with a disorganized arrangement and irregular size in psoriatic lesions.The expression of acid ceramidase also decreased in psoriatic epidermis.Conclusions The function of epidermal barrier in psoriasis is impaired,and to restore epidermal barrier function and enhance hydration may serve as an important adjuvant therapy of psoriasis.