Reactive infectious mucocutaneous eruption

Background

RIME is a mucosal or mucocutaneous eruption following Mycoplasma pneumoniae infections
- Other suspected causative infections include Chlamydophila pneumoniae, human metapneumovirus, human parainfluenza virus 2, rhinovirus, enterovirus, influenza A and B, COVID‐19, and adenovirus
Similar to a postinfectious Stevens-Johnson syndrome, though more common in younger patients with notable mucosal findings and absent or minimal cutaneous findings

Prodrome of fever, cough, and malaise lasting 3 to 13 days (median 8 days)
Usually two or more mucosal surfaces involved, including oral (most common, in 95% of cases), ocular (next most common, in around 90%), urogenital (about 60%), and anal or esophageal surfaces (least common)
- Oral: erosions, ulcers, vesicular or vesiculobullous lesions, or desquamation
- Ocular: bilateral conjunctivitis (often purulent), conjunctival injection, or hyperemia
- Urogenital: more commonly described in female patients
May have skin involvement, though absent in 1/3 and sparse in 1/2 of cases
- Vesiculobullous lesions are most common, followed by targetoid, papular, macular, and morbilliform
- Present on extremities and/or trunk

Routine investigations
Consider chest x-ray to assess for respiratory infection
Consider NP swab for viral PCR, Mycoplasma pneumoniae, and Chlamydophila pneumoniae
May need biopsy, though on biopsy it is indistinguishable from SJS/TEN

Evidence of an infectious trigger, with at least 2 of:
- Non-contributory medication history
- Erosive mucositis affecting 2 or more sites
- Vesiculobullous lesions or atypical targets affecting less than 10% of body surface area
Evidence of an infectious trigger can include history of cough, fever, malaise, and arthralgias in the preceding 7 to 10 days, or signs of respiratory infection on clinical examination
Supporting features include prodromal symptoms in the preceding 7 to 10 days, or histology ruling out other diagnoses

Not well studied
Supportive care: fluids, nutrition, and pain management
Low threshold for Dermatology consult to help with diagnosis and treatment
Consider Ophthalmology consult for patients with ocular involvement
In case reports or case series, patients have received high-dose corticosteroids (1-2 mg/kg IV methylprednisolone or 1 mg/kg p.o. prednisone for 3 to 5 days +/- taper), IVIG, cyclosporine, and etanercept