Patients with Mycoplasma pneumoniae-related erythema multiforme (MP-EM) have a distinct clinical presentation compared with those with non-MP EM, with more atypical and diffuse targets, severe and extensive mucositis, respiratory tract sequelae, and histologic findings similar to those of toxic epidermal necrolysis, according to the results of a retrospective cohort study published in the Journal of the American Academy of Dermatology.
The investigators sought to describe the differences between MP-EM and non-MP EM among patients admitted to their dermatology department with an EM diagnosis between 2000 and 2015. Epidemiologic, histologic, clinical, and follow-up data were compared in both groups of participants. A total of 33 patients with MP-EM were compared with 100 individuals with non-MP EM.
Disease onset in the winter occurred significantly more often among those with MP-EM (P =.003). Actually distributed lesions and typical targets were both significantly less common among participants with MP-EM vs those with non-MP EM (32% vs 88% [P <.0001], respectively, and 45% vs 74% [P =.01], respectively). Moreover, multiple (≥2) mucous membrane involvement was observed significantly more often in the MP-EM group than in the non-MP EM group (97% vs 60%, respectively; P <.0001), as were mucosal and respiratory tract sequelae (P <.05).
The mean length of hospital stay was significantly longer among MP-EM participants compared with non-MP EM participants (9.5 days vs 5.1 days, respectively; P =.0002). A toxic epidermal necrolysis-like pattern was detected among 100% (14 of 14) of MP-EM skin biopsies compared with 48% (10 of 27) of non-MP EM skin biopsies (P <.001).
The investigators concluded that the clinical aspects of MP-EM have been poorly described, with a distinctive clinical disease presentation compared with non-MP EM and histology that is similar to that of patients with toxic epidermal necrolysis. Management of mucosal involvement is essential in patients with MP-EM to prevent possible sequelae.
Amode R, Ingen-Housz-Oro S, Ortonne N, et al. Mycoplasma pneumoniae-related erythema multiforme: clinical and histological features. A single center series of 33 cases compared to 100 cases induced by other causes [published online March 17, 2018]. J Am Acad Dermatol. doi: 10.1016/j.jaad.2018.03.013