Reactive infectious mucocutaneous eruption secondary to Chlamydia pneumoniae infection in a 19-year-old: a case report.

Introduction. Reactive infectious mucocutaneous eruption (RIME) is a phenomenon that occurs predominantly in children and young adults following a bacterial or viral respiratory infection. RIME is most associated with Mycoplasma pneumoniae and generally presents with extensive mucosal and limited cutaneous involvement. Less commonly, infection with Chlamydia pneumoniae can trigger cutaneous eruptions but seldom leads to isolated mucosal involvement. Here, we describe a rare case of RIME mucositis secondary to C. pneumoniae respiratory infection. Case report. An otherwise healthy 19-year-old male presented with fever, cough, conjunctivitis, dysuria and oral mucositis with ulceration preventing food intake. C. pneumoniae was detected on a nasopharyngeal swab by a commercial multiplex PCR (BioFire Respiratory 2.1 Panel), while a broad workup of alternative infectious and autoimmune causes was unremarkable. Despite supportive care, antibiotics and initial steroid treatment, his mucositis necessitated hospital admission and eventually steroid regimen intensification before fully resolving. Conclusion. While rare, C. pneumoniae should be considered as a possible trigger of RIME in adolescents and young adults. Multiplex PCR assays capable of detecting atypical pneumonia pathogens such as C. pneumoniae and M. pneumoniae can assist in diagnosing patients presenting with RIME-compatible symptoms. Treatment involves supportive care, antibiotics and steroids if mucositis is severe. Steroid escalation may be beneficial in patients with slow-resolving mucositis.