A dermatologic assessment of 101 mpox (monkeypox) cases from 13 countries during the 2022 outbreak: Skin lesion morphology, clinical course, and scarring.

Background: In the 2022 mpox (monkeypox) outbreak, 79,000 global cases have been reported. Yet, limited dermatologic data have been published regarding lesion morphology and progression.

Objective: The objective of this study was to characterize skin lesion morphology, symptomatology, and outcomes of mpox infection over time.

Methods: The American Academy of Dermatology/International League of Dermatological Societies Dermatology COVID-19, Mpox, and Emerging Infections Registry captured deidentified patient cases of mpox entered by health care professionals.

Results: From August 4 to November 13, 2022, 101 cases from 13 countries were entered, primarily by dermatologists (92%). Thirty-nine percent had fewer than 5 lesions. In 54% of cases, skin lesions were the first sign of infection. In the first 1-5 days of infection, papules (36%), vesicles (17%), and pustules (20%) predominated. By days 6-10, pustules (36%) were most common, followed by erosions/ulcers (27%) and crusts/scabs (24%). Crusts/scabs were the predominant morphology after day 11. Ten cases of morbilliform rash were reported. Scarring occurred in 13% of the cases.

Limitations: Registry-reported data cannot address incidence. There is a potential reporting bias from the predilection to report cases with greater clinical severity.

Discussion: These findings highlight differences in skin findings compared to historical outbreaks, notably the presence of skin lesions prior to systemic symptoms and low overall lesion counts. Scarring emerged as a major possible sequela.