Mucormycosis

Background

  • Opportunistic invasive fungal infection, typically affecting immunocompromised patients (especially uncontrolled diabetics)[1]
  • Caused by saprophytic fungi (Mucorales)
    • Found in soil, bread mold, decaying fruits[2]
  • Fungal spores are dispersed in air → route of entry is inhalation[1]
    • Infection typically begins in nose and paranasal sinuses
    • Can also affect pulmonary, GI and CNS systems
  • Mucorales fungi have vascular proclivity, and can cause thrombosis → tissue and bone necrosis
  • Prognosis is poor, with 17-51% mortality[3], higher in cerebral involvement[4]

Clinical Types

  • 6 clinical types, based on location of infection[1][2]
    1. Rhino-orbital-cerebral (most common form)
    2. Pulmonary
    3. Gastrointestinal
    4. Cutaneous
    5. Disseminated
    6. Miscellaneous

Clinical Features

Palatal necrotic bone in a diabetic patient with rhino-orbital mucormycosis.
Single well-defined black necrotic eschar with slough on the hard palate in a patient with rhinocerebrocutaneous mucormycosis.
Frontal abscess and periorbital edema in a patient with mucormycosis
  • Rhinocerebral form initially mimics acute bacterial sinusitis (pain/swelling of cheeks and periorbital region)[2]
    • A much more rapid, extensive expansion of the fungus to the surrounding anatomy is classic
    • Can spread to orbits, oropharynx, nasopharynx, brain, nearby vasculature leading to → vision changes, nasopharyngeal and oropharyngeal ulceration or eschars, facial edema/pain, cranial nerve deficits, headache
    • Black palatal discoloration indicates palatal necrosis

Differential Diagnosis

Rhinorrhea

Headache

Common

Killers

Maimers

Others

Aseptic Meningitis

Evaluation

  • CT scan of sinuses with IV contrast can assist with diagnosis, often preferred over MRI as initial study as it is more readily available and more sensitive than MRI for bony erosions[5]
  • PCR-based techniques on invasively-obtained histologic samples demonstrating fungal elements is confirmatory[6]

Management

  • Emergent ENT consult for OR debridement (definitive treatment)
  • Start Amphotericin B 1mg/kg IV[2] OR
  • Aggressive resuscitation, airway management, and supportive care while in ED.
  • Hyperbaric oxygen therapy[4] and iron chelation (iron is required for fungal growth) may also help.[2]
    • Do not use deferoxamine (can worsen disease caused by certain fungal genera) - deferiprone is preferred

See Also

External Links

References

  1. 1.0 1.1 1.2 Selvamani M, Donoghue M, Bharani S, Madhushankari GS. Mucormycosis causing maxillary osteomyelitis. Journal of Natural Science, Biology, and Medicine. 2015;6(2):456-459. doi:10.4103/0976-9668.160039.
  2. 2.0 2.1 2.2 2.3 2.4 Motaleb HYA, Mohamed MS, Mobarak FA. A Fatal Outcome of Rhino-orbito-cerebral Mucormycosis Following Tooth Extraction: A Case Report. Journal of International Oral Health : JIOH. 2015;7(Suppl 1):68-71.
  3. 3.0 3.1 Bellazreg F, Hattab Z, Meksi S, et al. Outcome of mucormycosis after treatment: report of five cases. New Microbes and New Infections. 2015;6:49-52. doi:10.1016/j.nmni.2014.12.002.
  4. 4.0 4.1 Mohamed MS, Abdel-Motaleb HY, Mobarak FA. Management of rhino-orbital mucormycosis. Saudi Medical Journal. 2015;36(7):865-868. doi:10.15537/smj.2015.7.11859.
  5. Aribandi M, McCoy VA, Bazan C 3rd. Imaging features of invasive and noninvasive fungal sinusitis: a review. Radiographics. 2007 Sep-Oct;27(5):1283-96. doi: 10.1148/rg.275065189. PMID: 17848691.
  6. Walsh TJ, Gamaletsou MN, McGinnis MR, Hayden RT, Kontoyiannis DP. Early clinical and laboratory diagnosis of invasive pulmonary, extrapulmonary, and disseminated mucormycosis (zygomycosis). Clin Infect Dis. 2012 Feb;54 Suppl 1:S55-60. doi: 10.1093/cid/cir868. PMID: 22247446.