Management of Post Covid Mucormycosis/ Black Fungus
Covid 19 is a relatively new disease with fresh and evolving information being known on a dynamic basis. It is observed that some patients are being reported with a dreaded fungi disease called Mucormycosis. Covid associated Mucormycosis (CAM) had been associated with high mortality and morbidity.
Mucormycosis is a serious rare fungal infection caused by a group of moulds called mucormycetes. These fungi are darkly pigmented because of the presence of melanin in the cell wall. These moulds are ubiquitous and found in soil and air and even in the mucous of healthy people. The mucormycosis infection has been reported in medical literature even before the Covid pandemic, however a higher incidence of CAM infection has been noted in the second wave of Covid-19; it is associated with uncontrolled Diabetes Mellitus, indiscriminate and untimely use of high dose steroids and other immune modulatory therapy like Tocilizumab, prolonged oxygen therapy/prolonged ICU and mechanical ventilation, co-morbidities like post organ transplant or malignancy. Covid itself modulates the immunity of the individual by reducing the T-Cell.
The symptoms depend on the involved site. The fungus can infect sinuses, eyes, brain, and the lung, the intestine, cutaneous and soft tissues. When it affects the sinus, orbit, and brain it is called rhino-orbito-cerebral Mucormycosis. Nasal stuffiness, foul smelling discharge, nasal bleed, facial edema, pain and redness around the eye, double vision, protrusion of eyeball, loss of vision, restriction of eye movement, blackish discolouration over the palate and nose, toothache, loosening of tooth and jaw involvement are the usual presenting features. Fever, headache and altered mental status points towards the involvement of the brain are also experienced. To effectively treat this condition, a high index of suspicion and prompt diagnosis is crucial.
Diagnosis is reached by a combination of symptomatology and investigations. Diagnostic nasal endoscopy may show crusting, discoloured mucosa (either darkened or pale), insensate mucosa or decreased bleeding. Biopsies are taken, the specimen is sent for microbiological assessment with KOH staining and fungal culture. Histopathology reveals angioinvasion, haemorrhagic infarction, along with broad ribbon-like aseptate hyphae with irregular branching. Contrast or non-contrast, a CT scan provides the assessment of disease extend. MRI is preferred for the assessment of orbital or intracranial disease spread. It is important to assess vision and ocular movements.
Treatment of mucormycosis should be fast and aggressive. A multidisciplinary team including ENT surgeon, microbiologists, pathologists, intensivist, infectious disease specialists, ophthalmologists, maxillofacial surgeons, and neurosurgeons should be constituted for the best outcome. Both medical and surgical treatments are required. Aggressive surgical debridement of all the affected tissues is needed as per the radiological findings. E.g.: infection of the eye/ orbit, the whole eye has to be removed.
Medication plays an important role; antifungal medication to slow and halt the fungal spread is to be administered. Liposomal amphotericin B is the drug of choice with a dose of 5 - 10 my/ kg/ day with appropriate premedication. The other forms of Amphotericin are Amphotericin B deoxycholate (1- 1.5 my/kg/day), Amphotericin B lipid complex (5mg/kg/day) for 3 weeks. Thereafter, a patient should be shifted to oral Posaconazole tablet (400mg twice with a fatty meal or Isavuconazole (200mg twice for two days followed by 200 mg once daily). Posaconazole and Isavuconazole can be used as the first line of medication in case of amphotericin intolerance.
Routine monitoring of the renal function, electrolytes and timely appropriate correction of electrolyte imbalance is most important. Strict glycemic control under the guidance of an endocrinologist is of absolute necessity for a successful outcome. The progression of the disease should be closely monitored radiologically in periodic intervals.
Recommendations for prevention include:
- Dose duration and timing of steroid use should be consistent with National guidelines.
- Strict glycemic control should be maintained during and post Covid treatment.
- Maintenance and upkeeping of air handling units and surroundings of the patient should be taken care of.
- To avoid traumatic procedures like dental extraction or other nasal elective surgeries in immunocompromised post Covid patients. And if at all it is indicated, it should be done under strict glycemic control.
- Do not miss warning signs and symptoms and seek medical help immediately.