Puttick LM, Johnson GD, Walker L.
DOI: 10.2340/0001555566343346

We have studied the effect on the Langerhans´ cell (LC) population of topical 3% coal tar therapy. Biopsies were taken from psoriatic plaques and from controls with no skin disease before and after the application of 3% coal tar for one week; LC were identified by immunofluorescence using monoclonal antibody. LC counts expressed per unit epidermal surface length were similar in untreated psoriasis plaques and in normal skin. Differences in the LC population in paired biopsies from both patients and controls showed considerable variation following coal tar treatment but no consistent effect could be demonstrated.