Dermatologic and Ophthalmologic Treatment of Erythema Multiforme Major: A Case Report

Erythema multiforme major (EMM) is a rare type IV cytotoxic reaction targeting keratinocytes of the mucosal surfaces and the dermis. Dusky, targetoid lesions with central clearing are classically present, which may become blistered and rupture. The disease is usually self-limited and managed with supportive care and treatment of the underlying condition. The most common triggering factors are adverse reactions to medications, herpes simplex virus (HSV), and Mycoplasma pneumoniae. Rapid recognition of EMM is essential to avoid long-term complications. This case presents a 39-year-old male with a unique history of recent non-steroidal anti-inflammatory drug (NSAID) use, past infection with HSV-1, and an acute Mycoplasma pneumoniae infection. The patient developed painful lesions on the skin, oral mucosa, ocular surfaces, and urethra. The painful lesions caused complications with feeding and voiding. Initially, the triggering event was unclear. Supportive care was started. NSAIDs were discontinued and similarly-structured drugs were avoided. Treatments targeting Mycoplasma pneumoniae and HSV-1 were initiated while lab results were pending. Once the results returned, the treatment regimen of corticosteroids for inflammation, acyclovir for HSV-1, and azithromycin for Mycoplasma pneumoniae was continued. Vaseline was applied to open lesions. The patient was also treated with mouthwash consisting of aluminum (Al) hydroxide/magnesium (Mg) hydroxide/simethicone (400 mg/400 mg/40 mg). Topical 2% lidocaine gel with applicator was used to assist with urinary discomfort during voiding. Fentanyl was used for pain control. The patient successfully recovered and was discharged to follow-up with ophthalmology. Long-term sequelae including trichiasis, symblepharon, and punctal stenosis were noted during follow-up appointments.