Comparison of clinical characteristics of typical versus atypical SBO
| Typical SBO | Atypical SBO | |
|---|---|---|
| Age | Elderly | Middle-aged |
| Predisposing factors | DM more common than immunocompromised | DM, immunocompromised |
| Clinical features | Otorrhea, otalgia (severe, with pain out of proportion to the physical findings), hearing loss | Headache, atypical facial pain, cranial neuropathies, sinonasal symptoms in 25% |
| Cranial nerve involvement | VII most common | VI, IX, and X more common than VII |
| Pathogen | P aeruginosa in most cases; fungal more common in immunosuppressed patients without diabetes | S aureus slightly more common than P aeruginosa and fungal |
| Primary epicenter of disease process | EAC, petrous apex, and clivus | Central skull base, sphenoid bone, or clivus with or without evidence of regional infection of the sinuses, deep face, or oral cavity |
Note:—DM indicates diabetes mellitus.