Rhinology, skull-base boundaries and allergic disease
Rhinology questions test your ability to separate inflammatory from structural causes of nasal obstruction and to apply evidence-based medical therapy before surgery. Understand the ostiomeatal complex as the drainage pathway for the maxillary, anterior ethmoid, and frontal sinuses, and know that the sphenoid drains separately. Know the Lund-Mackay staging and that CT can provide objective disease and anatomical information when indicated, particularly for relevant surgical planning; its timing depends on the actual clinical question.
Differentiate CRS with and without nasal polyps. CRSwNP is often type 2 inflammation (eosinophilic), associated with asthma and aspirin-exacerbated respiratory disease (AERD: asthma, polyps, aspirin sensitivity). First-line therapy is saline irrigation plus intranasal corticosteroids; consider antimicrobials only where the actual evidence, suspected infection and relevant framework support them. Understand when to escalate to functional endoscopic sinus surgery (FESS) and the key surgical landmarks: middle turbinate, uncinate process, ethmoid bulla, and the skull base and orbit as the critical boundaries.
Traps: assuming all polyps are allergic (unilateral polyps in an adult warrant evaluation for inverted papilloma or malignancy); missing orbital or intracranial complications of acute bacterial rhinosinusitis (periorbital edema, proptosis, vision change, meningismus); and forgetting that aspirin desensitization can help AERD patients. Also know that allergic fungal rhinosinusitis produces eosinophilic mucin and requires surgical debridement plus medical therapy.
Rule of thumb: "Medical therapy first for CRS; surgery for failure, complications, or structural obstruction."
Worked example: A 40-year-old with bilateral polyps, asthma, and aspirin sensitivity has failed saline and intranasal steroids. Consider a short course of systemic steroids and, if refractory, FESS; discuss aspirin desensitization for long-term control.
Allergic and nonallergic mechanisms
Allergy questions focus on allergic rhinitis, testing, and immunotherapy. Understand the IgE-mediated pathway: allergen cross-links IgE on mast cells, causing histamine release and symptoms (sneezing, rhinorrhea, congestion, itchy eyes). Differentiate allergic rhinitis from nonallergic rhinitis (vasomotor, medication-induced, hormonal) and from infectious rhinitis.
Know the testing options: skin prick testing (fast, sensitive) and serum-specific IgE (useful when skin testing is not feasible). Interpret results in clinical context, positive tests without symptoms do not equal allergy. Treatment selection can include intranasal corticosteroids or antihistamines as appropriate; add leukotriene receptor antagonists in selected patients. Allergen immunotherapy (subcutaneous or sublingual) modifies disease and is indicated for refractory symptoms or poor medication tolerance.
Recognize anaphylaxis as a medical emergency: epinephrine first, then airway support and adjuncts. Know that aspirin-exacerbated respiratory disease involves asthma, polyps, and aspirin sensitivity, and that chronic urticaria is often idiopathic.
Traps: treating nonallergic rhinitis with immunotherapy; missing anaphylaxis in a patient with mild symptoms but airway involvement; and forgetting that skin testing can be falsely negative with antihistamine use.
Rule of thumb: "Test to confirm, treat symptoms first, and reserve immunotherapy for refractory or medication-limiting disease."
Worked example: A patient with seasonal sneezing, positive skin prick tests to grass, and inadequate response to intranasal steroids and antihistamines is a candidate for allergen immunotherapy.