Mycoplasma pneumoniae, a common cause of community-acquired pneumonia, may also be associated with extrapulmonary manifestations, among which Mycoplasma-Induced Rash and Mucositis (MIRM) stands out as a rare presentation that may not be accompanied by typical pneumonia, posing a diagnostic challenge. This report aims to present a case of MIRM. DPG, 13-year-old male, presented with dry cough for 10 days, and, 4 days earlier, onset of extensive ulcerated lesions in the lip region, with thick crusts, central linear fissures associated with intense pain and difficulty opening the mouth, coated tongue with involvement of inner labial mucosa, bilateral conjunctival hyperemia and purulent discharge, serosanguineous crusts in the nasal region, dysphagia and odynophagia. He also reported diffuse erythematous-violaceous maculopapular lesions on trunk, posterior cervical region, buttocks and scrotal sac. He had a single febrile peak 10 days earlier. He denied medication use. Physical examination: fair general condition, dehydrated, in pain, lung auscultation with scattered rhonchi; skin, oroscopy and rhinoscopy consistent with the description above. He evolved with new macules on face and limbs, as well as hematemesis, epistaxis, intense photophobia and poor oral intake. Chest X-Ray and echocardiogram were requested and were normal. Serologies for Epstein-Barr virus IgM, cytomegalovirus IgM and herpes simplex 1 and 2 IgM were positive. He was treated with acyclovir (later escalated to ganciclovir), ampicillin+sulbactam, tobramycin eye drops, topical acyclovir, lip laser therapy, analgesia and hydration. Serology for Mycoplasma pneumoniae was collected and returned positive one week later; azithromycin 10 mg/kg/day was started. He showed good response, with complete regression of lesions. This case shows the importance of recognizing MIRM as a differential diagnosis for conjunctival, mucosal and skin lesions, given the usual association of such symptoms with rheumatologic diseases and more common infectious etiologies. Diagnosis is the key step for introducing appropriate antimicrobial therapy and preventing exposure to multiple empirical treatments and prolonged hospitalization.
Longhinotti et al. (2026) studied this question.