Topical 10% Potassium Hydroxide for the Treatment of Childhood Molluscum Contagiosum

Abstract

Source: Short KA, Fuller C, Higgins EM. Double-blind, randomized placebo-controlled trial of the use of topical 10% potassium hydroxide solution in the treatment of molluscum contagiosum. Pediatr Dermatol. 2006;23:279–281; doi:10.1111/j.1525-1470.2006.00235.xMolluscum contagiosum is a common childhood viral cutaneous infection, resulting in increasing numbers of patient visits in recent years.1 To date, there is no single therapy that has been proven to be safe and effective for use at home. Investigators from the United Kingdom studied the efficacy of home treatment with 10% potassium hydroxide solution.Twenty healthy children aged 2 to 12 years were recruited into this double-blinded, placebo-controlled trial. None of the children were treated with other modalities before enrollment and none had facial molluscum. Lesions were treated twice daily; equal numbers of study children received either 10% KOH solution or placebo. In the treatment group, lesions in 7 of 10 patients cleared completely, while 2 children showed no improvement. The average time to clearance was 54 days. In the control group, lesions cleared in 2 of 10 patients, after 15 and 30 days, respectively. The proportion of patients who had clearing of their molluscum contagiosum was significantly greater among those receiving active treatment than those who received the placebo (P<.01). In the treatment group, nearly all children reported stinging, with 2 patients reporting severe stinging. Two patients in the treatment group developed transient post-inflammatory hyperpigmentation. There were no side effects noted in the control group.The authors conclude that topical 10% KOH solution may prove to be a safe, inexpensive, and noninvasive alternative treatment for molluscum in children.Dr. Dinulos has disclosed no financial relationship relevant to this commentary. This commentary does not contain a discussion of a commercial product/device. This commentary does not contain a discussion of an unapproved/investigative use of a commercial product/device.Most children with molluscum contagiosum do not require treatment since the lesions clear over a period of months to years. Nevertheless, many children are embarrassed by the molluscum and some complain of soreness and pruritus. Daycare providers and teachers may express concern about infecting other children. For these reasons, many parents and children may opt for treatment. Treatment options include physical modalities such as curettage, cryotherapy, and laser (pulse dye and CO2) and topical therapy such as cantharidin, imiquimod, tretinoin, silver nitrate paste, and salicylic acid.Potassium hydroxide is an alkali used to test for cutaneous fungal infections because of its ability to dissolve keratin. Open label studies indicate that KOH solution may be an inexpensive and effective therapy for home treatment of molluscum contagiosum.2 The present study showed 70% of patients were free of molluscum after 2 months of twice-daily application of 10% KOH solution. These data should be interpreted with caution, since the treatment produced significant adverse events (all children experienced stinging, 2 of them severe) and the study was not large enough to detect less frequent adverse reactions. For this reason alone, 10% KOH should not be regarded as safe for home use. Further studies should be conducted to determine if lower concentrations show comparable efficacy with fewer side effects.