The effect of silicol gel compared with placebo on papulopustular acne and sebum production. A double-blind study

Altogether 30 patients (19 females and 11 males), mean age 19 years, were divided randomly into two groups. All patients had chronic papulopustular acne of the face. A total of 15 patients were treated topically with Silicol gel for 20 min twice daily for 6 weeks and the remaining 15 patients were treated with a placebo gel in a similar fashion. A clinical evaluation was carried out at baseline, and after 2, 4 and 6 weeks of treatment. The clinical variables evaluated were as follows: number of comedones, papules, pustules and cysts on a standard area of the left cheek (area 5 x 5 cm) and measurement of sebum production on the same area by the use of Sebumeter SM 810 PC (Courage and Khazaka, Ltd, Germany). No concomitant treatment was allowed during the study period. One patient using Silicol gel withdrew after 2 weeks of treatment because of severe irritation of the facial skin, leaving 29 patients who could be evaluated. In the active group, the number of comedones decreased from a mean of 48.5 to 15.1 after 6 weeks of treatment. The corresponding figures for papules were 10.7 and 1.0, for pustules 6.8 and 0, and for cysts 0.6 and 0. In the placebo group no improvement could be observed. There was a highly significant difference in efficacy between the two groups (P < 0.001) in favour of the actively treated group. The mean sebum index was 193 at baseline and 88 after 6 weeks. Correspondingly in the placebo group the mean sebum index at baseline was 187 and after 6 weeks 179. This difference between the two groups was also statistically significant (P < 0.001). After a short follow-up period (3 months) no deterioration was observed in the 14 'active' patients, showing either complete cure or improvement.