Topical 20% KOH-An effective therapeutic modality for moluscum contagiosum in children

Introduction

Molluscum contagiosum is one of the commonest cutaneous viral infections especially seen in school going children. Although the disease may resolve spontaneously yet psychological effect of widespread lesions often warrants a therapeutical approach. Currently many modalities are available but these can be undertaken only in the hospital.This study was done to know the efficacy of topical 20% KOH aqueous solution in children having molluscum contagiosum and to know the duration of treatment and its side effects following topical application.

Materials and Methods

In this open study, 27 children with molluscum contagiosum were treated with topical 20% KOH aqueous solution. No other therapeutic procedures with systemic or topical agents were undertaken with this treatment. Parents were instructed to apply 20% KOH aqueous solution once daily at bed time with a cotton bud to all the lesions. They were advised to apply a small amount of solution to avoid spillage beyond the lesion. If accidentally spillage occurred, they were advised to wash the skin with cold water immediately. This treatment was continued till the lesions showed signs of inflammation or superficial ulceration. The assessment of therapeutic response was clinically seen at weekly intervals for first three weeks and then monthly for three months.

Results

In this open trial, 27 children were treated with topical 20% KOH aqueous solution once daily at bed time. The age of children in this trial varied from 8 months to 14 years (mean age - 5.8 years). Out of these 27 children 15 (55.6%) were males and 12 (44.4%) were females. 7 children (25.9%) were having a lesions on single site of the body whereas in 20 children (74.1%), multiple sites were involved. 24 children (88.9%) com-pleted the trial. All these children achieved com-plete clear-ance of the lesions after a mean period of 17 days. The develop-ment of in-flammation and ulceration time varied greatly ac-cording to the size and loca-tion of the le-sions. No re-currences were observed during follow up period. Most of the children re-ported a mild stinging sensa-tion lasting for 1 to 2 minutes after applica-tion. Of the dropouts, 2 children (7.4%) did not comply re-porting severe stinging sensation followed by ulceration and third child stopped the treatment as he developed sec-ondary bacterial infection. At the end of the trial local side effects were observed in 8 children (29.6%). These included secondary infection in 2 children (7.4%), severe stinging sensation in 2 children (7.4%) and hypopigmentation in 4 chil-dren (14.8%). Only 8 children (29.6%) had a his-tory of previous treatment whereas 19 children (7-0.4%) has had no treatment. Number of lesions in these children varied from 4 to 27 (mean 13). Time taken for complete disappearance of lesions varied from 13 to 22 days (mean 17 days).

Discussion

Molluscum contagiosum is caused by MC virus, the largest human virus and sole member of genus molluscipox.[1] Till date, there is no specific treatment available for molluscum contagiosum. Various chemical agents viz. podophyllin, tretinoin, cantharidin, trichloroacetic acid, silver nitrate, phenol, salicylic acid and tincture iodine have been used with variable results.[2],[3] Newer modalities in the form of electric cautery, cryosurgery and laser are also available.[4] All these therapeutic approaches have to be undertaken in the hospital and they have to be repeated depending upon their response. So the search for an alternative therapeutic modality that can be used at home especially in children is being required. Taking this into consideration we have undertaken an open trial with 20% KOH aqueous solution to be applied once daily at bed time in children having molluscum contagiosum.

Potassium hydroxide in varying concentration is routinely used by dermatologists to identify fungal elements in skin scrapings. KOH is known to penetrate deeply and destroy the skin because it dissolves keratin. It can also cause an irritant reaction in the skin varying with the concentration, body region and individual susceptibility.[5]

Of the 27 children with molluscum contagiosum, 24 (88.9%) completed the trial with clearance of all the lesions. Inflammation usually develop after a mean treatment period of 5 to 7 days. Parents were advised to stop the treatment as soon as inflammation or superficial ulceration became evident. Superficial ulceration could not be avoided even with brief careful application by the parents. Most children felt a transitory stinging sensation for 1 to 2 minutes shortly after the applications. Severe stinging sensation impeded further treatment only in 2 children. All parents reported that it was easy to apply the solution at home and all stated that they prefer to treat their children at home instead of using a more aggressive modality of treatment such as electric cautery, cryosurgery and laser.

Spontaneous clearance of molluscum lesions during the trial cannot be excluded but still a placebo controlled trial will be necessary to establish the exact therapeutic efficacy of KOH treatment. Nevertheless topical 20% KOH solution proved to be an effective, safe, inexpensive and non invasive alternative therapeutic modality in children. So evaluation of varying concentrations of KOH at various sites on the body to avoid unnecessary side effects should also be undertaken.