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All about Post Covid-19 Mucormycosis or Black Fungus  - Symptoms, Causes, Diagnosis, Precautions, Treatment

What is Mucormycosis or Black Fungus?

Mucormycosis, also known as Black Fungus, is a rare fungal infection caused by a mucor mould (mold) which is present everywhere - in soil, in air and even in the nose and mucus of healthy people. Mucormycosis is rare but often highly fatal with a mortality rate of almost 50%.


Why is Mucormycosis affecting recovered Covid-19 patients?


Covid patients are in many cases being given Steroids such as Methylprednisolone, Dexamethasone etc. to reduce inflammation in the lungs and to fight what is called the cytokine storm. Cytokine storm happens when the body's immune system goes into an overdrive and produces high levels of immune system proteins called cytokines that start to attack body’s own cells and tissues rather than just fighting the virus. Steroids work by reducing inflammation in the lungs and suppressing the immune response of the body which helps control the cytokine storm. As a side effect, steroids push up blood sugar levels in both diabetics and non-diabetics. Now, Covid-19 itself tends to increase blood sugar levels by reducing insulin secretion from the pancreas so the combined effect increases the blood sugar levels significantly and induces a phase of temporary Hyperglycemia.

Reduction in immune response and Hyperglycemia creates the environment in the body for mucor to grow leading to Mucormycosis. As a result, Mucormycosis is usually seen in elderly diabetics with poor sugar control but may occur in younger Covid-19 patients as well, especially those who require steroid treatment with high dosages for a prolonged period.


How does Mucormycosis progress in the body?


Typically Mucor enters the body through the nose and spreads towards the sinuses, orbit/eye and if not stopped here it can quickly spread to the brain, lungs and other organs. It causes tissue death by obstructing blood supply and the tissue becomes necrotic. If the dead and necrotic tissue is not removed timely it can spread very rapidly and can be life threatening especially in diabetic or severely immunocompromised individuals, such as cancer patients or people with HIV/AIDS.

Who are at greater risk of developing Mucormycosis?

  • Patients with uncontrolled Diabetes.

  • Patients who are on pre-existing Immunosuppressive therapy for some other disease or those who have any kind of immunodeficiency. 

  • Patients who were hospitalized for long duration, those on high flow oxygen and those who were treated with high dose Steroids. 

  • Use of tap water or unclean water in humidifier bottles for patients on oxygen support.

  • Overuse of intravenous antibiotics which can trigger fungal infection.

How can one diagnosis Mucormycosis early in post Covid-19 patients? What are the early signs and symptoms?

Symptoms of Mucormycosis in post Covid-19 patients can be divided into 2 parts - eye related and nose related

Eye related symptoms of Mucormycosis

  • Persistent redness and swelling inside the eyes - Congestion/Chemosis

  • Sudden onset of blurry vision or having double vision - Diplopia

  • Upper eyelid appearing droopy - Ptosis

  • Eye appearing to be bulged out - Proptosis 

  • Unable to move the eyes in different directions - Ophthalmoplegia 

  • Sudden total loss of vision – usually due to ophthalmic artery occlusion


Nose related symptoms of Mucormycosis

  • Feeling of dryness in the nose

  • Nasal blockage

  • Dark or blood tinged nasal discharge 

  • Facial puffiness / pain / numbness over the sinus area

  • Dark pigmentation around nostrils

  • Mouth ulcers and pigmentation on the hard palate

Krishna Netralaya's team of specialist Ophthalmologists bring together years of experience of treating all eye conditions.

How should one proceed if there are symptoms suggestive of Mucormycosis?


  • Immediate consultation with Ophthalmologist and ENT specialist for clinical evaluation.

  • MRI orbit and brain along with CT PNS are mandatory investigations to establish diagnosis.

  • Physician consultation for general systemic evaluation


How is Mucormycosis treated once diagnosed?

Once Mucormycosis is diagnosed, patient must be hospitalized and monitored very closely. 

  • Control diabetes and diabetic ketoacidosis 

  • Reduce steroids (if patient is still on) with aim to discontinue rapidly. 

  • Discontinue immunomodulating drugs 

  • Extensive Surgical Debridement - to remove all necrotic material.

  • Medical treatment- Intravenous Amphotericin B, Oral Posaconazole (newer antifungal with low risk of adverse effects but has less penetration and efficacy)

What precautions can be taken for prevention?

  • Avoid overuse or misuse of Steroids

  • Tight control of Diabetes

  • Monitor blood sugar levels very closely not only in diabetic covid but all patients who are on high dose steroids

  • Ensure good hygiene and clean water in humidifier bottles in patients on oxygen support.

  • Report immediately if any symptom appears.

At Krishna Netralaya we take care of your eyes with the best ophthalmic equipment from world's leading companies. 


Have more questions about Mucormycosis? Schedule a consultation with one of our Ophthalmologists.

Disclaimer: All information, provided above is for informational purposes only and is not intended to serve as a substitute for the consultation, diagnosis, and/or medical treatment of a qualified physician or healthcare provider. Read our full disclaimer here.

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