Recurrent Idiopathic Mucocutaneous Eruption (RIME) Associated with Mycoplasma Pneumoniae and Herpes Virus Coinfection: A Clinical Case Report

A 39-year-old male welder presented with a severe, acute mucocutaneous eruption following self-medication with amoxicillin for odynophagia and fever. Clinical examination revealed disseminated targetoid lesions with necrotic centers involving the skin, oral mucosa, and genitalia, initially suspicious for erythema multiforme major. Laboratory studies confirmed positive serologies for herpes simplex virus and demonstrated serological evidence suggestive of Mycoplasma pneumoniae infection, although polymerase chain reaction (PCR) confirmation was pending at the time of discharge. Thoracic imaging showed only chronic fibrotic bands related to occupational exposure. The patient was managed conservatively with systemic corticosteroids, antiviral therapy, topical wound care, and symptomatic mouthwashes, showing favorable short-term evolution. The final working diagnosis was probable Recurrent Idiopathic Mucocutaneous Eruption (RIME) secondary to strongly suspected Mycoplasma pneumoniae infection with concomitant herpes virus reactivation. This case highlights the diagnostic challenge of distinguishing RIME from other mucocutaneous syndromes, the importance of a multidisciplinary approach, and the necessity of microbiological confirmation to establish diagnostic certainty.