Postinflammatory Hyperpigmentation Following Mohs Micrographic Surgery: An Observational Study

Importance: Functional and cosmetic outcomes following Mohs micrographic surgery (MMS) are poorly studied in individuals with skin of color (SOC). Postinflammatory hyperpigmentation (PIH) may be long-lasting and highly distressing. SOC individuals are particularly susceptible to PIH following procedures. Objective:To characterize factors that contribute to the development of PIH following MMS in SOC. Design: This retrospective study included 72 SOC individuals with 83 cases of keratinocyte carcinoma treated with MMS between August 2020 and August 2021 at a single medical center in the Bronx, New York. Results: Postinflammatory hyperpigmentation following Mohs micrographic surgery was more common in Fitzpatrick skin types (FST) IV to V (48.0%) compared to FST I to III (18.2%; P=0.006). Grafts and granulation resulted in higher rates of PIH compared to linear repairs and flaps (87.5% vs 30.7%; P=0.003). Cases with postoperative complications resulted in higher rates of PIH compared to cases without (81.8% vs 29.2%; P=0.001). In a subset analysis of linear repairs, polyglactin 910 as a subcutaneous suture produced a higher rate of PIH compared to poliglecaprone 25 (46.2% vs 7.1%; P=0.015). Conclusions and Relevance: Individuals with SOC (FST IV to V) are more likely to develop PIH following MMS. Grafts and granulation lead to PIH more often than linear repairs and flaps. Postoperative complications significantly increase the risk of PIH. Surgeons should consider these risk factors during surgical planning in an effort to mitigate PIH in SOC individuals. Studies with larger sample sizes are indicated.