TRANSEPIDERMAL WATER-VAPOR LOSS IS NOT INCREASED DURING AND FOLLOWINGDITHRANOL IRRITATION

Dithranol is established as a very successful treatment for psoriasis. Its main disadvantages are irritation and staining at sites of applic ation. The aim of the present study was to elucidate further the mecha nism of dithranol-induced irritation, in particular to what: extent th is is related to an impairment of the skin barrier. Dithranol 3% in cr eam, paste and petrolatum was applied to the forearm skin of 20 volunt eers and left in situ for 1 h. Transepidermal water loss (TEWL) was me asured during a period of 2 weeks following dithranol application. In addition, a visual scoring system and colorimetry were used to assess erythema. The study showed conclusively that TEWL was not affected by the application of dithranol, even though pronounced erythema occurred .