Invasive fungal disease especially mucormycosis in covid

Invasive fungal disease especially mucormycosis in covid

Good morning Friends.
As we know there is a sudden surge in invasive fungal disease especially mucormycosis in severe covid cases, these are my few takes on this subject, that we can do to control this dreaded fungus at earliest stage and prevent blindness, deformity of face and CVA and at times death.

1. Mucor is a ubiquitous fungus present in nose but our immunity prevents any invasion by this fungus. So any condition which tunes our immunity down can lead to mucormycosis. So most commonly seen in diabetes, transplant patients, haematological conditions and malignancy.
   So why in covid?
   Covid causes immunosuppression by causing lymphopenia which inturn is due to reduced CD4 and CD8.
   It causes inflammatory cytokines surge, endotheliotis and a prothrombitic state. Many patients are in a diabetic state and with covid these patients are hit more harder on their immunity. To top up , injudicious or early use of steroid can play a significant role in surging mucormycosis in these immunocompromised patients.
2. Mucor is a fungus which needs iron to grow.
   We do not have ample of free iron in our serum. IL 6 leads to hyperferritemia. This leads more iron in serum for this fungus to grow . So that’s a need to know serum ferritin in all these patients
3. Strict glycemic control is very important and all patients on steroid especially are prone for this.
4. Early or injudicious use of steroid should be completely avoided , often we see people using steroid in the first few days of covid positive which can be very detrimental.
5. Diabetes impairs neutrophil function. It leads to chemotaxis, transmembrane migration and reduced superoxide production. It also leads to reduced binding of transferrin to iron in acidic conditions leading to more free iron in serum , an important raw material for mucor to grow.
6. So what are the risk factors for mucormycosis in covid 19 patients..
   A. Lymphopenia
   B. High and early initiation of steroid
   C. High levels of IL 6 AND FERRITIN
   D. Neutropenia.
   E. Uncontrolled diabetes
   F. Prolonged use of broad spectrum antibiotics
   G some report saying use of toclizumab 7 How to catch them early?
   Clinical findings –
   Nasal dryness and crusting is earliest sign and ALL THESE PATIENTS ( POST COVID) MANDATORY UNDERGO A NASAL ENDOSCOPY TO RULE OUT THIS. Black necrotic mass is very late to appear after thrombosis and when the tissue is already dead and devitalised.
   Patients may complain of paraesthesia and anaesthesia of cheek , gum and teeth and it should be taken very seriously.
   Later facial swelling and periorbital swelling, severe headache, nasal blockage intraoral pus and mobile teeth may be seen .
7. Investigations
   Although CT scan is most widely done, a nasal Endoscopy and gadolinium enhanced MRI is very crucial to pick devitalised tissue and normal tissue. This becomes more necessary when surgery is planned to limit the extent of debridement and prevent unnecessary tissue removal and at the same time avoid leaving too much dead tissue inside which even medical management will have difficult time to manage.
   Early stage only signs of sinusitis will be seen.
   Later bony erosion in maxilla and spenoid bone ( both commonly involved in mucormycosis) can be seen and finally orbital and intracranial extension.
8. Surgery is mainly to remove devitalised tissue, debulking of infected tissue, to establish HPE, AND theoretically allowing for faster action of antifungal against a small burden of fungus remaining.
9. Finally antifungal medications in confirmed mucormycosis cases.
   Some one suggested use of posaconazole as prophylactic or step down from amphotericin B.
   If given can be used as 300 mg Bd on day 1 FU with 300 mg OD for 6 weeks.
   I am attaching a medical treatment sheet for the use of liposomal ampho B
   All these patients need continuous, serial nasal Endoscopy and at times scans to catch them early and for long term follow up.

I think we all together can prevent lot many blindness, CVA and death if this fungus be tamed timely.
Thanks for reading this unusual long post

Dr Uttam Agarwal
ENT Surgeon
Belle Vue Clinic*