Mucormycosis

Mucormycosis is any fungal infection caused by fungi in the order Mucorales.:328 Generally, species in the Mucor, Rhizopus, Absidia, and Cunninghamella genera are most often implicated. The disease is often characterized by hyphae growing in and around blood vessels and can be potentially life-threatening in diabetic or severely immunocompromised individuals. 'Mucormycosis' and 'zygomycosis' are sometimes used interchangeably. However, zygomycota has been identified as polyphyletic, and is not included in modern fungal classification systems. Also, while zygomycosis includes Entomophthorales, mucormycosis excludes this group. Mucormycosis frequently infects the sinuses, brain, or lungs. While infection of the oral cavity or brain are the most common forms of mucormycosis, the fungus can also infect other areas of the body such as the gastrointestinal tract, skin, and other organ systems. In rare cases, the maxilla may be affected by mucormycosis. The rich blood vessel supply of maxillofacial areas usually prevents fungal infections, although more virulent fungi, such as those responsible for mucormycosis, can often overcome this difficulty. There are several key signs which point towards mucormycosis. One such sign is fungal invasion into the blood vessels which results in the formation of blood clots and surrounding tissue death due to a loss of blood supply. If the disease involves the brain, then symptoms may include a one-sided headache behind the eyes, facial pain, fevers, nasal congestion that progresses to black discharge, and acute sinusitis along with eye swelling. Affected skin may appear relatively normal during the earliest stages of infection. This skin quickly becomes reddened and may be swollen before eventually turning black due to tissue death. Other forms of mucormycosis may involve the lungs, skin, or be widespread throughout the body; symptoms may also include difficulty breathing, and persistent cough. In cases of tissue death, symptoms include nausea and vomiting, coughing up blood, and abdominal pain. Predisposing factors for mucormycosis include HIV/AIDS, uncontrolled diabetes mellitus, cancers such as lymphomas, kidney failure, organ transplant, long term corticosteroid and immunosuppressive therapy, cirrhosis energy malnutrition, and deferoxamine therapy. Despite this, however, there have been cases of mucormycosis reported with no apparent predisposing factors present. As swabs of tissue or discharge are generally unreliable, the diagnosis of mucormycosis tends to be established with a biopsy specimen of the involved tissue. If mucormycosis is suspected, amphotericin B therapy should be immediately administered due to the rapid spread and high mortality rate of the disease. Amphotericin B is usually administered for an additional 4–6 weeks after initial therapy begins to ensure eradication of the infection. Isavuconazole was recently FDA approved to treat invasive aspergillosis and invasive mucormycosis.