The immunohistochemical effect of a hydrocolloid occlusive dressing (DuoDERM E) in psoriasis vulgaris.

The topical application of a hydrocolloid occlusive dressing (HCD) has been shown in various studies to have an antipsoriatic effect as monotherapy but especially in combination with a topical corticosteroid. The aim of the present study was to assess the effect of 3 weeks of HCD monotherapy at the immunohistochemical level. Ten patients were treated. Before and after treatment, a biopsy was taken, and immunohistochemical stainings were carried out with markers for epidermal growth, keratinization, inflammation and endothelium. Suprabasal expression of keratin 16, the number of cycling epidermal cells and the number of polymorphonuclear leucocytes and T lymphocytes tended to decrease during treatment. The endothelial markers did not change during HCD treatment. This study confirms the antipsoriatic effect of HCD and demonstrates that its effect upon some markers of inflammation, epidermal proliferation and keratinization is modest.