Mucormycosis

Mucormycosis, also known as black fungus, is a severe fungal infection that may cause fulminant fungal sinusitis, usually in people who are immunocompromised. It is most curable when diagnosed early. Symptoms depend on where in the body the infection occurs. It most commonly infects the nose, sinuses, eyes and brain resulting in a runny nose, one-sided facial swelling and pain, headache, fever, blurred vision, bulging or displacement of the eye (proptosis), and tissue death. Other sites of infection may include the lungs, stomach and intestines, and skin. The fatality rate is about 54%.

It is spread by spores of molds of the order Mucorales, most often through inhalation, contaminated food, or contamination of open wounds. These fungi are common in soils, decomposing organic matter (such as rotting fruit and vegetables), and animal manure, but usually do not affect people. It is not transmitted between people. Risk factors include diabetes with persistently high blood sugar levels or diabetic ketoacidosis, low white blood cells, cancer, organ transplant, iron overload, kidney problems, long-term steroids or use of immunosuppressants, and to a lesser extent in HIV/AIDS.

Diagnosis is by biopsy and culture, with medical imaging to help determine the extent of disease. It may appear similar to aspergillosis. Treatment is generally with amphotericin B and surgical debridement. Preventive measures include wearing a face mask in dusty areas, avoiding contact with water-damaged buildings, and protecting the skin from exposure to soil such as when gardening or certain outdoor work. It tends to progress rapidly and is fatal in about half of sinus cases and almost all cases of the widespread type.

Mucormycosis is usually rare, but is now ~80 times more common in India. People of any age may be affected, including premature infants. The first known case of mucormycosis was possibly the one described by Friedrich Küchenmeister in 1855. The disease has been reported in natural disasters, including the 2004 Indian Ocean tsunami and the 2011 Joplin tornado. During the COVID-19 pandemic, an association between mucormycosis and COVID-19 has been reported. This association is thought to relate to reduced immune function during the illness and may also be related to glucocorticoid therapy for COVID-19. A rise in cases was particularly noted in India.

Generally, mucormycosis is classified into five main types according to the part of the body affected. A sixth type has been described as mucormycosis of the kidney, or miscellaneous, i.e., mucormycosis at other sites, although less commonly affected.

Signs and symptoms of mucormycosis depend on the location of the infection in the body. Infection usually begins in the mouth or nose and enters the central nervous system via the eyes.

If the fungal infection begins in the nose or sinus and extends to the brain, symptoms and signs may include one-sided eye pain or headache and may be accompanied by pain in the face, numbness, fever, loss of smell, a blocked nose or runny nose. The person may appear to have sinusitis. The face may look swollen on one side, with rapidly progressing "black lesions" across the nose or upper inside of mouth. One eye may look swollen and bulging, and vision may be blurred.

Fever, cough, chest pain, and difficulty breathing, or coughing up blood, can occur when the lungs are involved. A stomach ache, nausea, vomiting, and bleeding can occur when the gastrointestinal tract is involved. Affected skin may appear as a dusky reddish tender patch with a darkening centre due to tissue death. There may be an ulcer, and it can be very painful.