2017 Volume 127 Issue 1 Pages 23-30
We report seven cases of contact dermatitis due to benzoyl peroxide (BPO), which occurred after the application of gels containing BPO such as therapeutic agents for pimples (Bepio® gel and Duac® combination gel). None of the patients had any history of atopic dermatitis or had previously used skincare products containing BPO. Patch tests using 1% BPO in petrolatum and the BPO gels revealed that four of the patients were allergic to BPO; in the remaining 3 patients, BPO acted only as an irritant. In the former four patients, the onset of allergic contact dermatitis occurred 9 to 24 days after the initial application of the causative substance, while in the remaining three patients it took only two days to induce irritant contact dermatitis. The clinical findings of the allergic and irritant dermatitis induced by these gels were very similar. For diagnostic purposes, it is essential to confirm the duration of application and the skin reactions induced via patch testing. The frequency of allergic contact dermatitis to BPO was 2.7% at our clinic; thus, dermatologists should be aware of this allergenicity when prescribing BPO gels.
