Efficacy of triclosan soap against superficial dermatomycoses and scabies : a placebo-controlled study among 228 primary school children in Kilombero district, Mororgoro region, Tanzania

Background: The present placebo-controlled double-blind study was performed to assess the clinical efficacy of Triclosan against selected superficial dermatomycoses and scabies. The overall effect of regular soap use was also evaluated. Methods: 820 Tanzanian primary school children were examined for the presence of skin disorders. The clinical presentation of the dermatoses was documented. Samples of suspected dermatomycoses were examined microscopically using KOH. Quality control and culture were performed, and the MIC's of placebo soap and Triclosan against Malassezia spp. were assessed in vitro. The children with superficial dermatomycoses or scabies were selected for this trial. They received either bar soap containing Triclosan (active group) or placebo soap during a period of 8 weeks. They were followed-up after 1 and 2 months. Results: Among the 820 examined children, superficial dermatomycoses were the most common diagnoses, with a total prevalence rate of 33.9%. The prevalence rates of tinea versicolor, tinea capitis, corporis and pedis were 26.2%, 5.5%, 2.6%, 3.2% respectively. Triclosan soap was not significantly more effective against any of the selected dermatoses. Overall cure rates of tinea versicolor, tinea capitis, corporis and pedis were 28.4%, 61.1%, 56.3% and 36.8% respectively. In tinea versicolor soap use improved the overall degree of infection significantly (p = 0.000). The proportion of negative microscopic results increased from 19.0 to 51.6%. Neither the placebo nor Triclosan were efficacious against Malassezia spp. in vitro at relevant concentrations. In tinea capitis the overall degree of infection also improved significantly (p = 0.001). The addition of Triclosan yielded only slightly, non-significantly superior results. In the Triclosan group, the proportion of negative tinea capitis samples increased from 22% to 64%, whereas it decreased from 57% to 53% in the placebo group. In tinea corporis the size of the largest lesion decreased from 2.2 cm to 1.0 cm in the active group whereas it increased in the placebo group. In tinea pedis the cure rate was non-significantly higher for active than for placebo soap (86% versus 56%). The prevalence of scabies was 1.5%. All 6 children included in this study showed an overall tendency towards improvement with either soap. <br>Conclusions: In tinea versicolor the lack of superior efficacy of Triclosan soap is consistent with the lack of in vitro efficacy of Triclosan. The overall improvement may be due to unspecific effects associated with soap use such as a reduction of the amount of superficial skin lipids. In other dermatomycoses, the overall improvement can be explained by the elimination of infectious pathogens from the integument. The in vitro activity against certain dermatophyte spp. explains the slight beneficial effect of Triclosan versus placebo soap. The lack of significance may be due to the mode of application and the common use of vaseline. The results therefore confirm the usefulness of soap, but do not justify the addition of Triclosan to treat superficial skin mycoses and scabies.

Author dc:creator

• Dinkela, Almuth

Contributors dc:contributor

• Hatz, Christoph

• Dermatomycoses
• Triclosan, soap, Tanzania

Repository record source_url

https://freidok.uni-freiburg.de/data/2463

OAI identifier oai:identifier

oai:freidok.uni-freiburg.de:2463