A novel dithranol formulation (Micanol): the effects of monotherapy and UVB combination therapy on epidermal differentiation, proliferation and cutaneous inflammation in psoriasis vulgaris.

Abstract

Micanol, in which dithranol is micro-encapsulated in crystalline monoglycerides, is easy to wash off and staining and irritation are inconspicuous. These features make it appropriate to use in an out-patient setting. In this study the immunohistochemical effects of this new dithranol formulation were studied and compared with UVB and the combination of these therapies in skin biopsies of 8 patients with psoriasis. Markers for epidermal differentiation, proliferation and cutaneous inflammation were assessed. The present study suggests that Micanol predominantly had diminishing effects on inflammation markers, hardly affecting the epidermis. UVB had a broad spectrum of reductions. It is feasible that the combination resulted in various synergistic effects. Previous studies, however, revealed a relative persistence of the inflammatory infiltrate with more effects on epidermal processes following dithranol treatment. Based on the present study and on previous studies, it is hypothesised that Micanol delivers the active substance more directly in the dermal infiltrate, leaving the epidermis relatively unaffected. This might explain the low irritancy of Micanol treatment.