Mucha-Habermann disease: a pediatric case report and proposal of a risk score.

Febrile ulceronecrotic Mucha-Habermann disease (FUMHD) is a rare inflammatory dermatological disease. A case of a 13-year-old boy with FUMHD possibly triggered by mycoplasma infection is presented. Based on FUMHD cases identified in a MEDLINE literature search, demographic, treatment, and outcome data were analyzed. An FUMHD mortality risk score is proposed based on the likelihood ratios of risk factors for a fatal outcome. Our FUMHD case had marked leukopenia and thrombocytopenia at admission. He recovered without systemic immunosuppressive treatment. Literature review revealed 119 FUMHD cases. Overall lethality was 14/119 (12%, CI 6-17%), and lethality in children was lower (1/54, 2%, CI 0-6%) compared to adults (13/65, 20%, CI 11-31%). Risk factors for a fatal outcome (likelihood ratio; P) were sepsis (24.97, P < 0.001), adult vs. pediatric patient age (11.19; P = 0.001), systemic involvement (19.97, P < 0.001), and mucosal involvement (4.58; P = 0.032). The proposed FUMHD mortality risk score = Age/10 + 4 + 4 (if systemic involvement) + 1 (if mucosal involvement) was discriminative (sensitivity 93%, specificity 77%). In FUMHD, immune-suppressive treatment intensity should be balanced against the mortality risk, as infectious complications are a frequent cause of death.