Comparative study of 5% and 2.5% potassium hydroxide solution for molluscum contagiosum in children.

Background: Molluscum contagiosum (MC) is a pediatric viral infection that is fairly contagious. Although various treatment methods are available, the presence of facial lesions limits options of therapy.

Aim: We aimed to test an alternative treatment consisting of application of two different concentrations of potassium hydroxide (of KOH 5% solution and of KOH 2.5% solution) aqueous solution.

Methods: In this study we evaluated the effectiveness and side-effects of daily applications of potassium hydroxide (KOH) aqueous solution at 2.5% and 5% concentrations, twice daily in 29 children with MC. Out of a total of 29 patients with molluscum contagiosum included in the study, 13 patients in the 2.5% KOH group and 12 patients in the KOH 5% group completed the study. Families were instructed to apply potassium hydroxide twice a day. The assessment of response and side-effects were performed on days 0, 15, 30, 45 and 60 (visits were numbered 1, 2, 3, 4 and 5, respectively) and one month after.

Results: We had a total of 11 (44%) patients who completely recovered after the fifth visit. While eight (66.7%) of these 11 patients were in the 5% treatment group, three (23.1%) patients were in the 2.5% treatment group, and there was a statistically meaningful difference (p < 0.047). Patients with fewer lesions remitted better (p < 0.05). When number of lesions were taken into consideration, difference between the two treatment groups appeared after the fourth visit (p < 0.001). There were no statistical differences between the two groups with respect to side-effects (p = 0.682).

Conclusions: Potassium hydroxide solution at a concentration of 5% was more effective than 2.5% in our patients. The treatment was well-tolerated on the face with the advantage of administration of lower concentrations. This study suggests potassium hydroxide may be a more preferable mode of treatment for molluscum contagiosum lesions on the face.