Mucormycosis
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Mucormycosis (formerly Zygomycosis) is a rare but catastrophic, angioinvasive fungal infection caused by moulds of the order Mucorales (e.g., Rhizopus, Mucor).
It affects immunocompetid patients, particularly those with Uncontrolled Diabetes (DKA). It is a Surgical Emergency requiring immediate debridement.
Clinical Scenario: The Diabetic with a Black Nose
A 45-year-old man with poorly controlled Type 1 Diabetes is admitted with DKA (pH 7.1). On day 2, he complains of right-sided facial pain and double vision. Examination reveals a black patch on the roof of his mouth and a swollen right eye.
Key Teaching Points
- **Diagnosis**: Rhino-Orbital-Cerebral Mucormycosis until proven otherwise.
- The **Black Eschar** is pathognomonic (tissue infarction from fungal invasion of vessels).
- **Acidosis** releases free iron, which fuels fungal growth.
- **Action**: Urgent MRI + ENT surgical debridement + IV Amphotericin B.
Image Integration Plan
| Image Type | Source | Status |
|---|---|---|
| Management Algorithm | AI-generated | PENDING |
| Pathophysiology (Angioinvasion) | AI-generated | PENDING |
| Clinical Photo (Palatal Eschar) | Web Source | PENDING |
| Histopathology (Ribbon Hyphae) | Web Source | PENDING |
[!NOTE] Image Generation Status: Diagrams illustrating the '90 degree branching' are queued.
Mucor vs Aspergillus
| Feature | Mucormycosis | Aspergillosis |
|---|---|---|
| Hyphae | Broad, Non-septate (Aseptate) | Narrow, Septate |
| Branching | Right Angle (90°) | Acute Angle (45° / Dichotomous) |
| Appearance | Ribbon-like | Tree-like |
| Vessels | Angioinvasive (Thrombosis) | Angioinvasive |
- Incidence: Rare globally, but endemic in India (surge seen during COVID-19 pandemic).
- Mortality: 50-80% (nearly 100% if CNS involvement or no surgery).
- Risk Factors:
- Diabetes (DKA): Most common risk.
- Steroids: High dose.
- Iron Overload: Or use of Deferoxamine (fungi use it as a siderophore).
- Neutropenia: Leukaemia/Chemo.
- Inhalation: Spores form environment enter sinuses.
- Growth: In acidic, sugar-rich environments (DKA), fungi thrive.
- Angioinvasion: Hyphae invade blood vessel walls -> Vasculitis -> Thrombosis -> Ischaemic Necrosis.
- Spread: Rapid spread from sinuses -> Orbit -> Brain (Cavernous sinus).
Rhino-Orbital-Cerebral (Commonest)
Other Forms
- Nasal/Oral: Look for the black eschar. (May need endoscopy).
- Eyes: Check movements (Frozen eye?), Pupil reflex, Vision.
- Neuro: Cranial nerves V (numbness), VII (palsy).
- Nasal Endoscopy: Visualize necrosis.
- Biopsy (Urgent):
- KOH Mount: Direct microscopy shows broad, aseptate hyphae.
- Culture: Often negative (fungi are fragile). Don't wait for culture to treat.
- MRI / CT:
- Shows sinus opacification and bone destruction.
- MRI helps define orbital/brain extension.
"Medical Emergency - Time is Tissue"
A. Surgical (Crucial)
- Aggressive Debridement: Remove all necrotic tissue until bleeding bone/tissue is reached.
- Often requires maxillectomy or orbital exenteration (remove eye).
- Repeat debridement often needed daily.
B. Antifungal Therapy
- Liposomal Amphotericin B: Drug of choice. high dose (5-10 mg/kg/day).
- Monitoring: Renal function / Potassium (nephrotoxic).
- Posaconazole / Isavuconazole: Second line (Step down).
- (Note: Voriconazole - used for Aspergillus - does NOT work for Mucor).
C. Risk Factor Reversal
- Correct DKA aggressively.
- Stop steroids if possible.
- Stop Deferoxamine.
- Cavernous Sinus Thrombosis.
- Internal Carotid Artery occlusion.
- Disfigurement: From surgery.
- Death.
- Extremely high mortality.
- Survival depends entirely on: 1. Reversing immunosuppression (DKA) 2. Early Surgery.
- ECMM/MSG Global Guidelines: Diagnosis and management of mucormycosis (2019).
- Cornely OA, et al. Lancet Inf Dis.
What is Black Fungus? It is a very rare but aggressive fungal infection. It lives in soil and dust. Most people breathe it in every day without issue. However, if your immune system is weak (especially if you have uncontrolled diabetes with high acid levels), the fungus grows rapidly.
Why is it called Black Fungus? Because it kills the body tissue as it grows, turning the nose or roof of the mouth black.
Is it dangerous? Yes, extremely. It spreads from the nose to the eyes and brain within days. It is life-threatening.
How is it treated? We have to act very fast.
- Strong drips: Anti-fungal medicine (Amphotericin).
- Surgery: This is the hardest part. Surgeons must cut away all the dead/infected tissue to stop the spread. This sometimes means removing parts of the nose, palate, or even the eye. It is drastic, but it saves lives.
- Cornely OA, et al. Global guideline for the diagnosis and management of mucormycosis. Lancet Infect Dis. 2019.
- Roden MM, et al. Epidemiology and outcome of zygomycosis: a review of 929 reported cases. Clin Infect Dis. 2005.
- Spellberg B, et al. Recent advances in the management of mucormycosis. F1000Res. 2017.