Effect of short-contact anthralin therapy on ultraviolet B irradiation of psoriasis.

The influence of short-contact anthralin on the therapeutic effect of ultraviolet B irradiation (Sylvania UV-21 tubes) was investigated with the half-body comparison method in fifteen outpatients with plaque-type psoriasis. The lesions on the right or left half of the body were exposed to one of the topically applied compounds (either anthralin and 2% salicylic acid in petrolatum or 2% salicylic acid in petrolatum alone) for 10 to 30 minutes daily. Of the fifteen patients, five (Group I) were given 0.3% anthralin and five (Group II) received increasing concentrations of anthralin (0.3, 1, 3%); the other five (Group III) were patients who had failed to respond to ultraviolet B therapy alone, and for them a new clearing treatment was started with the addition of anthralin in increasing concentrations (0.3%, 1%, 3%). Only two patients in Group I, one patient in Group II, and one in Group III showed a moderately better clearance of psoriasis on the short-contact anthralin side. Irritation of nonaffected skin by anthralin was common only during the first week of the treatment. Staining of clothes and bedding occurred.