Mycoplasma Pneumonia with MIRM

• Prominent mucositis, usually with sparse or even absent cutaneous involvement. 

• Primarily affects children and young patients (mean age 12 years), more commonly males (1) and often in winter (2)

•  Only approximately 25 percent of patients with M. pneumoniae infections present with a mucocutaneous eruption (1)

Classic MIRM is characterized by severe mucositis and variable, but generally sparse, cutaneous lesions. Most patients experience a prodrome of cough, malaise, and fever for approximately one week prior to the onset of their mucocutaneous eruption [1)

• Oral involvement is nearly universal, with hemorrhagic crusting of the lips and erosions on the tongue and buccal mucosa although  isolated erosions and ulcers can occur (1)

• Ocular involvement is common, most often characterized by a purulent bilateral conjunctivitis, photophobia and eyelid edema may also occur. (1)

Urogenital lesions occur in approximately 60 percent of patients and can affect the vulva, vagina, any part of the penis (including the urethral meatus), and scrotum (1)

Ophthalmology Consult

• Ophthalmology was consulted for  eye pain with decreased vision/photophobia 

• INITIALLY → Tx w/ erythromycin ggt prior to ophthalmology evaluation

  • No signs of corneal involvement or uveitis

  • Txd with tobradex and saline drops. 

• Course: waxing-waning course of photophobia and pain, patient re-evaluated with noted epithelial involvement of the corneas with dendritic pattern, highly suspicious for herpetic keratoconjunctivitis. 

  • Right Eye viral culture positive for HSV-1. 

  • Tx prednisolone ophthalmic suspension as well as IV ganciclovir. 

** Of note, herpetic keratitis, typically a result of reactivation of latent disease, may re-occur in 25-50% of patients within 2 years and will require close follow up.

Dermatology Consult

• Upon presentation to ED, pt with oral lesion thought to be cold sore in the setting of family hx of fever blisters and cold sores → significant mucositis

• Initially → Triamcinolone for oral lesions, magic mouthwash, sucralfate, petroleum jelly, tylenol. 

• Pt later developed penile involvement → hydrocortisone for penile lesions.

• Sores both oral and penile had a waxing and waning course and eventually + swab both for HSV-1

• 7 day course of IV ganciclovir improved both oral and penile lesions

• At time of discharge, using vaseline gauze and petroleum jelly for barrier protection and additional 14 day course of po acyclovir.

Infectious Disease Consult

• Initially → RVP positive for Mycoplasma pneumoniae, Bcx negative, Throat swab positive for group A strep initially treated with azithromycin and amoxicillin (interim IV ampicillin 2/2 decreased po intake)

• Mucositis course complicated by HSV-1 → tx with IV ganciclovir

• Mucositis further complicated on day 20 admission with new onset fever, hypotension, tachycardia with + BCs of Gram Positive cocci in clusters identified as Staph Epidermidis and confirmed with second blood culture. 

• Likely second to compromised oral mucosa integrity and self-introduction, possibly from picking at scabs → completed 7 day course of IV Vancomycin followed by Ampicilin prophylaxis for 3 days until noted clinical improvement of oral mucosa. 

Presentation & Diagnosis

• Diagnosis of mycoplasma pna

  •  fever, cough, fatigue, and positive auscultatory findings, cxr

  • PCR, IgM/G/A

  • **Generally young male pts in winter

• Diagnosis of MIRM

  • Mucocutaneous eruption with <10 percent body surface area involvement

    • few vesiculobullous lesions or scattered, atypical, targetoid lesions

  • Involvement of two or more mucosal sites (oral, ophthalmic, genital)

  • Clinical and laboratory evidence of M. pneumoniae infection

Pathophysiology

• A minority of patients with M. pneumoniae infection develop mucocutaneous lesions → complex underlying pathophys, w/ exact pathogenesis unknown. (1)

• 2  primary mechanisms have been proposed:

Indirect

• most commonly accepted 

• Infection → immune response →  tissue damage

• Polyclonal B cell proliferation and antibody production→  immune complex deposition and complement activation → skin damage

• Molecular mimicry between M. pneumoniae P1-adhesion molecules and keratinocyte antigens (3,4)

Direct

•  Bacteria present at mucocutaneous sites →  local release of inflammatory cytokines and tissue damage. 

• Requires hematogenous spread from the respiratory tract to the skin 

• the variable extent of mucocutaneous involvement and frequent involvement of distant sites make this mechanism unlikely.

Differential

• Differential when you see MIRM → aka mucositis with a rash,  biopsy is not helpful, hx and clinical appearance are

  • EM 

  • SJS/TEN

  • RIME (reactive infectious mucocutaneous eruptions)

  • Herpetic gingivostomatitis

  • Paraneoplastic pemphigus

  • Hand, foot, and mouth disease

  • Aphthous ulcer

Treatment

• Supportive care: mIVF (close ins/outs), adequate pain relief, antipyretics, supportive nutrition

  • Close monitoring for super infections

  • Appropriate consultations: ophthalmology, ID, derm

  • Workup for underlying rheumatologic or immune compromise if not improving 

  • Steroids (not used in this pt) are freq used and given systemically to decrease inflammation and pain but evidence lacking, if used 5-7 pred 1 mg/kg/day with no taper

  • Other reported treatments: plasmapheresis, cyclosporin, IVIG (1)

• Close inpatient monitoring for superimposing infection

  • Antibiotics as appropriate

• Close outpatient follow up upon discharge

Hospital Course