Mucormycosis Neuroopthalmology emergency

Predisposing factors: diabetes mellitus, DKA, neutropenia, chronic immunosuppression, organ transplantation, hematologic malignancy, hemodialysis, burns, treatment with deferoxamine.

Five clinical forms-- rhinal-orbital-cerebral (one form), pulmonary, disseminated, gastrointestinal, cutaneous. ROC is most common (44 %) usually due to inhaled fungal spores that generate into hyphae and invade the blood vessels causing thrombosis, infarction, and necrosis.

Signs and symptoms-- fever, headache, periorbital pain, acute opthalmoplegia, proptosis, periorbital edema, visual loss, conjunctival redness, and trigeminal anesthesia. Facial or periorbital pain is seen only in one to thirds, against earlier belief. Acute orbital cellulits may be heralded or accompanied by blood tinged nasal discharge or epistaxis. The characteristic necrotic eschar in the nose or hard palate is often missed; these are seen in only 52 % in the first 72 hours. X rays show nonspecific findings such as sinus mucosal thickening or orbital infiltration, occassionally bone destruction, opthalmic vein thrombosis, in the setting of sinusitis or orbital cellulitis. Diagnosis is based on biopsy and H & E staining. If an eschar is not seen, consider a blind nasal biopsy. Lack of pain or bleeding during the biopsy is highly suspicious for mucormycosis. Treatment should be started immediately including amphotericin, correction of risk factors, surgical debridement, and possibly hyperbaric oxygen. Bad prognostic indicators are treatment delay of more than six days, intracranial symptoms such as seizures or hemiplegia, bilateral sinus involvement, facial necrosis, underlying leukemia, or deferoxamine therapy.