The most important risk factors, and therefore the populations affected, are diabetics and those with hematologic malignancy. Diabetes, specifically with ketoacidosis, is the main risk factor. (1,2) Neutrophil dysfunction, along with hyperglycemia and an iron rich environment induced by ketoacidosis allows for the fungi to avoid the immune system and thrive in a substrate rich environment. (3) Retrospective studies have reported over 80% of cases in those with diabetes, and 40% of those who previously did not have known history of the disease. (1) Hematologic malignancy, especially those with acute myelogenous leukemia are also at increased risk. Other immunosuppressive states and burn victims without a protective skin barrier are also at risk.
The three most common forms of disease are rhinocerebral, pulmonary and cutaneous. The most common is rhinocerebral. This is the classic disease state seen in patients with DM or DKA. Inhalation of spores leads to invasion of the sinuses. This leads to typical symptoms of sinusitis. However the hallmark feature is a necrotic eschar on the palate, nasal turbinates or external skin. Seeing this feature does not rule out mucormycosis, but absolutely rules it in. If cerebral or orbital invasion occurs, cranial nerve or ophthalmologic symptoms can develop. If these are seen in combination, it should be considered mucormycosis unless proven otherwise. (1,2)
The pulmonary form of the disease is rapidly progressive and has a high mortality rate (76%). (1) Manifestations would be similar to other forms of pneumonia, specifically invasive pulmonary aspergillosis. It would be difficulty to sore this out in the emergency department, but could be considered in the right patient population or in those who are failing to improve while on broad-spectrum antibiotics. (1,2)
The cutaneous form of mucormycosis can have variable presentations, but again if nerotic eschars are present, this needs to be in the differential. If invasion of the underlying soft tissues, muscle and bone occur, it can cause significant pain or present similar to necrotizing fasciitis. (1)
Source control is an important component of treatment. Consultation with subspecialties such as otolaryngology, ophthalmology or pulmonology should occur promptly. If history and physical exam are suggestive this should occur prior to further studies because this is a highly fatal disease that is a time sensitive emergency, often requiring extensive debridement. CT scans of affected areas can help in the diagnosis but do not show specific findings. Anti fungal therapy with the lipid formulation of amphotericin B at 5 mg/kg/day is the agent of choice. (2)
This is a rare disease that may never be encountered in the career of the emergency physician. It nevertheless should remain in the differential because of its high mortality rate that approaches 80% in invasive disease. While other forms of the disease may be hard to distinguish, the rhinocerebral form has hallmark physical exam findings that can aid in the diagnosis. For a terrific review of a case of mucormycosis, please use this link to the EM:RAP Podcast.
- Petrikkos G, Skiada A, Lortholary O, Roilides E, Walsh TJ, Kontoyiannis DP. Epidemiology and clinical manifestations of mucormycosis. Clin Infect Dis. 2012 Feb;54 Suppl 1:S23-34
- Long B, Koyfman A. Mucormycosis: what do emergency physicians need to know? Am J Emerg Med. 2015 Aug 28
- Ibrahim AS, Spellberg B, Walsh TJ, Kontoyiannis DP. Pathogenesis of mucormycosis. Clin Infect Dis. 2012 Feb: 54 Suppl1:S16-22
Submitted by Dr. Michael Craddick, PGY-2