A double-blind placebo-controlled study of ketoconazole + desonide gel combination in the treatment of facial seborrheic dermatitis.

BACKGROUND: The pathobiology of seborrheic dermatitis is rooted in a peculiar inflammatory reaction to Malassezia spp. Both topical corticosteroids and antifungals are routinely used with success, either singly or in combination. OBJECTIVE: To assess the effect of a new combination therapy in this condition. METHODS: Eighteen patients with facial seborrheic dermatitis were treated in a pilot double-blind trial with an anhydrous gel containing the combination of 2% ketoconazole and 0.05% desonide (n = 9) or the unmedicated gel (n = 9). The products were applied once daily for 3 consecutive weeks. Disease severity was assessed at the start and weekly during treatment, as well as 2, 4 and 8 weeks after the end of treatment or at the time of recurrence. The overall clinical assessments were performed using a visual analogue scale. Objective measurements included squamometry X after harvesting the stratum corneum and the erythema index yielded by narrow-band reflectance spectrophotometry. Data were evaluated in an intent-to-treat analysis. RESULTS: The combination therapy yielded reductions in the overall clinical symptom severity of 49, 84 and 92% after 1, 2 and 3 weeks of treatment, respectively. The corresponding improvements with the placebo gel were significantly smaller (p < 0.01), reaching 23, 29 and 42% at successive 1-week intervals. At the end of the 3-week treatment, the clinical signs had completely subsided in 6/9 patients treated with the medicated gel and in only 1/9 patients using the placebo gel. Thus, the clinical response rate was significantly faster (p < 0.01) with the combination therapy than with the vehicle. Differences between the treatment groups using objective noninvasive assessments were also significantly (p < 0.01) in favor of the combination therapy. The squamometry X measurements showed 47, 67 and 74% improvements with the combination gel after 1, 2 and 3 weeks, respectively. The corresponding values with the placebo gel were 34, 46 and 53%, respectively. The erythema index was almost completely reduced to normal at week 2 of treatment in contrast with about 50% reduction with the unmedicated vehicle. None of the patients reported any side effects. CONCLUSION: The combination of ketoconazole with desonide in an anhydrous gel is well tolerated and proves to be significantly more effective than the vehicle for treating facial seborrheic dermatitis. The fast response to treatment and the limited additional improvement between weeks 2 and 3 of the treatment suggest that this combination product may be efficacious with once daily applications for 2 weeks. These data call for expanded studies comparing each single compound, the vehicle and the combination therapy.