A 52-year-old male diabetic presents with a week-long history of fever, headache, confusion, facial nerve palsy with pain and a black, purulent nasal discharge. He is referred to ICU for his deteriorating level of consciousness.
Give the most likely diagnosis. (20% marks)
List four predisposing factors. (10% marks)
List the specific management of this condition. (40% marks)
a) "Give the most likely diagnosis" for 20% of the mark really only gives enough time for two words. Fortunately, you only need one: mucor. Not much else presents as encephalitis/meningitis "and a black, purulent nasal discharge".
Having said this, "mucor mimics" do exist. Firstly, it could be another Zygomycete (Branscomb, 2002, lists Rhizopus, Absidia, Saksenaea and Cunninghamella). Secondly, it could be a bacterial infection causing necrotising fasciitis, or it could be the black eschar of an airway burn, or the patient might have recently had a nasogastric tube which had produced a nasty intranasal pressure area with necrosis. But these are not especially plausible.
b) List four predisposing factors is worth only 10% of the marks, but these are reasonably easy to earn. The college have already given you one, by volunteering a history of diabetes. Mucor likes to extend along blood vessels, and even more so when the vessels are full of sugar. In total, Branscomb (2002) lists the following nine predisposing factors:
In addition to this, the college also add
c), "List the specific management of this condition" calls for some additional thinking, as it is worth 40%. Interestingly, the college had listed imaging and cultures in this section, even though those (undoubtedly important) elements are investigations which don't themselves manage anything. Still, if one is expected to list the investigations, they would be:
Craig et al (2019) give an excellent overview of management options, classifying them in the following manner:
Craig, John R. "Updates in management of acute invasive fungal rhinosinusitis." Current opinion in otolaryngology & head and neck surgery 27.1 (2019): 29-36.
Branscomb, Robert. "An overview of mucormycosis." Laboratory Medicine 33.6 (2002): 453-455.
Tragiannidis, A., and A. H. Groll. "Hyperbaric oxygen therapy and other adjunctive treatments for zygomycosis." Clinical Microbiology and Infection 15 (2009): 82-86.