To determine risk factors affecting mortality in acute invasive fungal sinusitis.

This observational cohort study was conducted over a five-year period.

Of 109 recruited patients, 90 (82.6 per cent) had diabetes mellitus. Predominant fungi were zygomycetes (72.6 per cent) with Rhizopus arrhizus being most common. Of the patients, 12.8 per cent showed a positive biopsy report from radiologically normal sinuses. Factors affecting mortality on multivariate analysis were: female sex (p = 0.022), less than two weeks between symptoms and first intervention (p = 0.01), and intracranial involvement (p = 0.034). Other factors significant on univariate analysis were: peri-orbital swelling (p = 0.016), restricted ocular movements (p = 0.053), intracranial symptoms (p = 0.008), posterior disease (p = 0.058), imaging showing ocular involvement (p = 0.041), fungus being zygomycetes (p = 0.050) and post-operative cavity infection (p = 0.032). Bilateral, palatal and retromaxillary involvement were not associated with poor prognosis.

Diagnosis of acute invasive fungal sinusitis requires a high index of clinical suspicion. Recognition of factors associated with poor prognosis can help when counselling patients, and can help initiate urgent intervention by debridement and antifungal therapy. Post-operative nasal and sinus cavity care is important to reduce mortality.