Scars are frequently found as late sequelae in individuals affected by the 2022 mpox outbreak.

Background: The 2022 mpox outbreak continues, and while progress has been made in prevention strategies and potential treatment options, data on late sequelae following mpox are scarce.

Objective: This analysis aimed to assess the incidence of scar formation in individuals affected by the 2022 mpox outbreak.

Methods: All individuals diagnosed with mpox at the Department of Dermatology at the Medical University of Vienna in 2022 were included in this analysis. Follow-up data were collected throughout November 2023. 'Scar formation' was defined as having at least one scar at the former active mpox lesions.

Results: At our clinic, 28 cases of mpox presented between June 2022 and October 2022 and exclusively occurred in men who have sex with men (100%, 28/28), of whom 46% (13/28) were living with HIV, and 32% (9/28) were using pre-exposure prophylaxis (PrEP). Secondary bacterial infection of mpox lesions was suspected in six individuals, and all received systemic antibiotics. Overall, 26 were followed up in November 2023 after a median time of 15 months, and scar formations were found in 43% of cases.

Conclusions: Our data provide insights into the late yet cumulating disease burden caused by the 2022 mpox outbreak. Highly effective prevention strategies are warranted to overcome the mpox epidemic and its potential late sequelae.