British Journal of DermatologyVolume 186, Issue 3 p. e113-e113 Plain Language SummaryFree Access A model to understand postinflammatory hyperpigmentation better First published: 07 March 2022 https://doi.org/10.1111/bjd.20987AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Abstract Linked Article: Vellaichamy et al. Br J Dermatol 2022; 186:508–519. Postinflammatory hyperpigmentation (PIH) is an extremely common disease that involves the development of dark spots on the skin at sites of previous injury or disease. This is the result of overproduction of melanin in the skin (the pigment that gives skin its normal colour). There are limited options for treating it and this is because not very much is known about how it develops. PIH can have a significant impact on patient’s quality of life, especially in individuals with skin of colour. In this study, we test and refine a model we had previously developed in order to understand this disease better. Based in the USA, we recruited 29 patients to test our model, which includes light- and colour-based technology to assess the amount of pigmentary response in the skin. We induced pigmentation using trichloroacetic acid (TCA) and assessed the response using a variety of measures. Our findings suggest that in future studies investigating how PIH develops and looking at potential agents that might be used to treat it the best concentration of TCA to apply is 30%. We found that our model could demonstrate a dose–response relationship between the degree of insult and the severity of the resulting pigmentation. This study also shows that microRNAs (small pieces of genetic material that play an essential role in a large number of biological processes) can be helpful tools in our quest for a better understanding of this disease and also, possibly, as targets for treatment. Volume186, Issue3March 2022Pages e113-e113 RelatedInformation