Rhinology, Sinus, and Allergy
Core concepts
Understand sinus anatomy and drainage pathways, especially the ostiomeatal complex as the common drainage site for frontal, maxillary, and anterior ethmoid sinuses. Know the difference between acute bacterial rhinosinusitis (symptoms persisting beyond 10 days or worsening after initial improvement) and viral rhinosinusitis. Master allergic rhinitis pathophysiology (IgE-mediated) and treatment ladder: intranasal corticosteroids first-line, antihistamines for symptoms, immunotherapy for refractory cases. Recognize red flags for invasive fungal sinusitis (immunocompromised, black eschar, orbital or cranial nerve involvement) as a surgical emergency. Be familiar with epistaxis management by location-anterior (Kiesselbach plexus, cautery/pressure) versus posterior (sphenopalatine artery, packing or ligation).
Traps
Questions often overuse antibiotics for viral sinusitis; the key is duration and pattern. Another trap is confusing allergic fungal rhinosinusitis (chronic, polyps, eosinophilic mucin) with invasive fungal disease (acute, angioinvasive, immunocompromised). Also watch for nasal polyps being attributed to infection when they suggest chronic rhinosinusitis with polyps or aspirin-exacerbated respiratory disease.
Worked example
A diabetic patient has facial pain, black necrotic eschar, and orbital swelling. This suggests invasive fungal sinusitis, requiring urgent surgical debridement and antifungal therapy. Rule of thumb: black eschar in an immunocompromised patient equals emergency.