Ernest presented a case of a young woman, with no medical history, presenting with acute onset severe mucositis (eyes, mouth, urogenital) after a few days of viral prodrome and one day after taking azithromycin prescribed by her PCP. Her skin findings were almost non-existent and the bulk of her symptoms were isolated to the mucosa. Her presentation is consistent with a diagnosis of MIRM!

MIRM (Mycoplasma Induced Rash and Mucositis)

Epidemiology

• 25% of patients with mycoplasma pneumoniae experience extra-pulm manifestations
• Coined different terms, incomplete SJS, Fuchs Syndrome, MIRM
• Mean age: Young (median 11-12 yo), male predominance.

Presentation

• Universally will have some sort of prodrome: cough, malaise, fever preceding eruption of lesions by ~ 1 week.
• Manifestations: variable, mucositis alone, prominent mucositis with sparse skin involvement. Skin involvement tends to be very rare and on the milder side, presenting as vesiculobullous, targetoid, papules, macules. Rarely morbilliform.
• Majority of cases are severe mucositis alone.
• Involvement: Oral (100%), ocular (92%), urogenital (78%)

Diagnosis

• Clinical Dx
• Mycoplasma IgM/IgG helps but their sensitivity and specificity are highly variable.

Management:

Supportive care (especially pain control, hydration/nutrition, infection prevention) plus treat the underlying cause (mycoplasma)!

• Systemic corticosteroids (mixed data so generally not recommended first line)
• IVIG (has been used in very severe cases))

Prognosis

• Better than SJS/TEN, 81% will make a full recovery.
• Blindness/residual visual impairment is possible but less common vs SJS/TEN

Key distinguishing features:

MIRM: Young, slight male preference, usually 7 days after infection, predominantly mucosal involvement, very little cutaneous involvement, better prognosis vs SJS/TEN.

SJS/TEN: Any age, female preference, usually 1-3 weeks after drug exposure, diffused skin involvement (Nikolsky sign) + mucosal involvement, more severe ocular manifestation.

Please refer to this review article for more background on this condition.