Background Delayed pressure urticaria (DPU) is characterized by the appearance of typical painful skin lesions (weals) after pressure stimulus. Oral corticosteroids are effective treatments but long-term therapy is problematic. A new topical formulation of clobetasol propionate 0·05% in thermophobic foam (CF) (Olux®) has recently become available. The foam is easy to apply, with low skin residues.
Objectives To evaluate in a double-blind placebo-controlled trial the efficacy, tolerability and safety of CF in the topical treatment of DPU.
Methods Twenty-six subjects with a positive history of DPU (13 men, mean age 44 years) were enrolled in a 4-week trial. CF or the corresponding placebo were applied twice daily. Drug application was performed in the most affected areas and in a target area where a standardized pressure challenge test was performed at baseline and at week 4. Efficacy was evaluated by scoring skin lesions regarding erythema, oedema and itching (0, no sign; 4, severe signs) and by calculating the area of the pressure challenge-induced lesion. Safety was evaluated by measuring plasma levels of adrenocorticotropic hormone (ACTH) and cortisol.
Results CF significantly (P = 0·0001) reduced lesion area by 84% in comparison with baseline values and by 97% in comparison with the placebo group values. Lesion area in the CF group was reduced from 144 cm2 to 21 cm2 at the end of the study. No significant differences in lesion area and clinical lesion scores were observed in the placebo group (lesion area 201 cm2 at baseline; 216 cm2 after 4 weeks). A significant clinical improvement was observed in all treated skin areas in the CF group. Mean ± SD erythema score was reduced by CF from 1·8 ± 0·6 at baseline to 0·6 ± 0·5 at the end of the treatment (P = 0·001). Similar modifications were observed also for oedema (from 1·6 ± 0·6 to 0·2 ± 0·5) and itching score. Nonsignificant modifications of plasma levels of ACTH, cortisol and glucose were observed in both study groups, in comparison with baseline values. No adverse events were recorded during the trial in either treatment group.
Conclusions CF is effective, safe, convenient and well tolerated in the short-term treatment of DPU.