Nocardia sinusitis is exceptional, as a Medline search revealed only one published case. The authors report a case of sphenoid sinusitis complicated by infratemporal fossa abscess, which raised several diagnostic problems.

The patient was referred with temporal headache, subacute trigeminal neuralgia and subsequent infectious syndrome. Computed tomography imaging revealed left sphenoid sinusitis with osteolysis and infratemporal fossa abscess, as well as suspicious lung nodules suggestive of the initial site of infection. Bacteriological specimens obtained by endoscopic sphenoidotomy confirmed the presence of Nocardia nova. A favourable outcome was observed in response to targeted antibiotic therapy.

Sphenoid sinusitis with infratemporal fossa abscess is an exceptional mode of presentation of nocardiosis, illustrating the polymorphic clinical features of this disease. Bacteriological examination of samples taken directly from the organ concerned, in this case, by sphenoidotomy, is the only formal diagnostic criterion. Antibiotic therapy with intravenous imipenem/amikacin, followed by oral sulfamethoxazole/trimethoprim (Bactrim Forte^®) for several months, is the key to successful management.