Clinical Features of Mucormycosis
This information is intended for health care providers.
There are five major clinical forms of mucormycosis, of which rhinocerebral (sinuses and brain) and pulmonary (lung) infections are the most common. The clinical hallmark of mucormycosis is the rapid onset of tissue necrosis (tissue death) with or without fever. Necrosis is the result of invasion of blood vessels and subsequent thrombosis (blood clotting).
- Rhinocerebral mucormycosis is most commonly seen in neutropenic (low white blood cell counts) cancer patients, hematopoietic stem cell transplant (HSCT) recipients, and patients with diabetic ketoacidosis. Symptoms may include unilateral (one-sided) facial swelling, headaches, nasal or sinus congestion or pain, serosanguinous (bloody) nasal discharge, and fever. As the infection spreads, ptosis (“drooping eyelid”), proptosis (eye dislocation), loss of extraocular muscle function, and vision disturbance may occur. Necrotic black lesions on the hard palate (upper inside of mouth) or nasal turbinate (nasal cavities) and drainage of black pus from eyes are useful diagnostic signs.
- Pulmonary (lung) mucormycosis generally occurs in patients with hematologic malignancy (blood cancers) or profound neutropenia and in those who have been on steroid therapy. The symptoms include fever, cough, chest pain, and dyspnea (shortness of breath). Angioinvasion results in necrosis of tissue, which may ultimately lead to cavitation (formation of empty spaces) and/or hemoptysis (coughing up blood).
- Gastrointestinal mucormycosis is less common, is thought to arise from ingestion of the organism, and occurs in patients who are severely malnourished and in transplant recipients. The stomach, colon, and ileum are the most commonly involved sites. The symptoms are varied and depend on the site affected, but nonspecific abdominal pain and distention associated with nausea and vomiting are the most common symptoms. Gastrointestinal basidiobolomycosis, a rare type of infection, has been reported in Arizona. Its symptoms are non-specific, including fever, abdominal pain, diarrhea, and constipation, and abdominal imaging will reveal masses in the gastrointestinal tract. The diagnosis requires the microscopic examination and culture of biopsy specimens.
- Cutaneous (skin) mucormycosis may be primary or secondary. Primary infection is usually caused by direct inoculation of the fungus into disrupted skin and is most often seen in patients with burns or other forms of local skin trauma. Primary infection produces an acute inflammatory response with pus, abscess formation, tissue swelling, and necrosis. The lesions may appear red and indurated (hardened) and often progress to black eschars (dead tissue). Secondary cutaneous infection is generally seen when the pathogen spreads hematogenously (in the blood). In hematogenously disseminated infection, the lesions typically begin as an erythematous (reddened), indurated, and painful cellulitis (skin inflammation) and then progress to an ulcer covered with a black eschar.
- Disseminated mucormycosis may follow any of the four forms of mucormycosis described above but is usually seen in neutropenic patients with a pulmonary infection. The most common site of spread is the brain, but metastatic necrotic lesions have also been found in the spleen, heart, and other organs. Clinical manifestations include lethargy, changes in mental status, or obtundation (reduction in mental status) with or without a sudden onset of focal neurological signs.