Intra-epidermal accumulation of polymorphonuclear leukocytes in persistent palmoplantar pustulosis during treatment with acitretin.

Six patients with persistent palmoplantar pustulosis were treated with acitretin, and the clinical response was compared with the effect on the intra-epidermal accumulation of polymorphonuclear PMN leukocytes. A prompt improvement of pustule formation and subsequently decreased scaling and erythema was seen in all patients. Following discontinuation of therapy, a relapse occurred within 2 weeks. With dosages of 45 or 55 mg/day, the clinical scores were only slightly better than with 25 or 35 mg/day. In patients using 25 mg acitretin a day, the leukotriene B4-induced intra-epidermal accumulation of polymorphonuclear leukocytes was not affected. However, a dosage of 35 mg/day resulted in a significant inhibition of PMN accumulation, dosages of 45 and 55 mg/day causing an even more pronounced inhibition of this process. Although the effect of different dosages of acitretin is not clearly expressed in the severity scores, the dose-dependent effect on PMN chemotaxis in vivo might be of relevance when combination therapies are considered, in order to achieve a complete clinical clearance.