Sinusitis & Rhinitis
A Step 2 CK–focused ENT lesson on sinusitis and rhinitis, built around the board decisions: viral vs. acute bacterial rhinosinusitis criteria, first-line antibiotics, can't-miss complications (mucormycosis, orbital involvement), and rhinitis management with intranasal corticosteroids first-line.
Overview: rhinosinusitis vs. rhinitis
Rhinosinusitis is inflammation of the nasal mucosa and paranasal sinuses, which almost always occur together (hence the combined term). Acute rhinosinusitis (ARS) lasts <4 weeks; chronic disease lasts ≥12 weeks. The overwhelming majority of acute cases are viral (common cold) and self-limited — only about 0.5–2% develop bacterial superinfection, so the board task is knowing when to withhold vs. give antibiotics. Rhinitis is inflammation of the nasal mucosa itself; allergic rhinitis is the most common chronic form. Expect the classic decision points: separating viral from acute bacterial rhinosinusitis (ABRS), choosing the first-line antibiotic, recognizing dangerous sinusitis complications (orbital cellulitis, invasive fungal disease), and managing rhinitis — where intranasal corticosteroids are first-line.
- Pathogens (ABRS): S. pneumoniae, H. influenzae, M. catarrhalis
- Symptoms: purulent nasal discharge, congestion, facial pain/pressure (worse bending forward), maxillary tooth pain, hyposmia
- Diagnose ABRS clinically if ANY: (1) symptoms ≥10 days without improvement; (2) severe onset — fever ≥39°C (102°F) + purulent discharge/facial pain for ≥3–4 days; (3) "double worsening" — new fever/worsening after initial improvement
- Imaging is NOT routine — CT only for suspected complications, recurrent/chronic disease, or surgical planning
- Viral/uncomplicated: symptomatic — analgesics, saline irrigation, intranasal corticosteroids; topical decongestants only ≤3–5 days
- ABRS first-line: amoxicillin-clavulanate (5–7 days in adults)
- Penicillin allergy: doxycycline or a respiratory fluoroquinolone (levofloxacin, moxifloxacin); avoid macrolides/TMP-SMX (resistance)
- Watchful waiting is acceptable for uncomplicated ABRS with reliable follow-up
Viral vs. bacterial vs. chronic rhinosinusitis
| Feature | Viral ARS | Acute bacterial (ABRS) | Chronic RS |
|---|---|---|---|
| Duration | <10 days, improving | ≥10 days, or severe, or double-worsening | ≥12 weeks |
| Discharge | clear → mucopurulent, resolving | persistent purulent | variable, ± nasal polyps |
| Imaging | none | none (unless complication) | CT sinuses; ENT referral |
| First-line Rx | symptomatic (saline, INCS) | amoxicillin-clavulanate | INCS + saline irrigation |
| Board pearl | most cases — no antibiotics | watchful-waiting option | think polyps / Samter triad |
Vignette: A 34-year-old woman has 12 days of nasal congestion, thick yellow-green discharge, and left maxillary pressure worse when bending forward. Symptoms briefly improved around day 6, then worsened, with T 38.9°C. Vision is normal, extraocular movements intact, and there is no proptosis.
Diagnosis: Acute bacterial rhinosinusitis — meets criteria (symptoms >10 days and "double worsening").
Next best step: Diagnosis is clinical — start amoxicillin-clavulanate and add saline irrigation/intranasal corticosteroids. Do NOT order a sinus CT or plain films in uncomplicated disease. Reserve imaging + IV antibiotics for red flags: visual changes, proptosis, ophthalmoplegia, altered mental status, or forehead swelling (Pott puffy tumor).
Vignette: A 58-year-old man with poorly controlled diabetes presents in DKA with facial pain, left nasal congestion, a black necrotic eschar on the turbinate/hard palate, periorbital swelling, and new ophthalmoplegia.
Diagnosis: Invasive (rhino-orbito-cerebral) mucormycosis — Rhizopus/Mucor; biopsy shows broad, non-septate (aseptate) hyphae branching at wide (~90°) angles. Classic in DKA and neutropenia.
Next best step: This is a surgical emergency — urgent surgical (endoscopic) debridement + IV liposomal amphotericin B + aggressive correction of the DKA. Do not delay for extensive workup. (Contrast: Aspergillus — septate hyphae with acute-angle (~45°) branching — in neutropenic/immunocompromised hosts.)
- Allergic rhinitis: IgE-mediated (type I hypersensitivity); sneezing, itchy nose/eyes, clear rhinorrhea, congestion; exam shows pale, boggy, bluish turbinates, allergic shiners, and a transverse nasal crease ("allergic salute")
- Diagnosis: clinical; confirm with skin-prick testing or serum allergen-specific IgE
- Management (first-line = intranasal corticosteroids, most effective): allergen avoidance → INCS → oral/intranasal antihistamines → leukotriene antagonist → allergen immunotherapy if refractory
- Nonallergic (vasomotor) rhinitis: triggered by temperature change/odors/alcohol, no itching, negative allergy testing; treat with intranasal azelastine, intranasal corticosteroids, or ipratropium (rhinorrhea-predominant)
- Rhinitis medicamentosa: rebound congestion from topical decongestant (oxymetazoline) use >3–5 days — treat by stopping the decongestant + intranasal corticosteroids
- Nasal polyps + asthma + aspirin sensitivity → Samter triad (aspirin-exacerbated respiratory disease)
Samter triad (aspirin-exacerbated respiratory disease) = the "3 A's":
- Asthma
- Aspirin / NSAID sensitivity
- nAsal polyps
Suspect it in an adult with recurrent nasal polyps and asthma who develops bronchospasm and rhinorrhea after aspirin or NSAIDs. Mechanism: COX-1 inhibition shunts arachidonic acid toward the 5-lipoxygenase pathway → excess leukotrienes. Management: leukotriene-modifying drugs, aspirin/NSAID avoidance, and consideration of aspirin desensitization; polyps commonly recur after surgical removal.
Comparing the rhinitis types
| Feature | Allergic rhinitis | Vasomotor (nonallergic) | Rhinitis medicamentosa |
|---|---|---|---|
| Cause/trigger | allergens (IgE) | temperature, odors, alcohol | topical decongestant >3–5 days |
| Itching/sneezing | prominent | absent | absent |
| Allergy testing | positive | negative | negative |
| Turbinates | pale, boggy, bluish | variable | erythematous, swollen |
| First-line Rx | intranasal corticosteroids | azelastine / INCS / ipratropium | stop decongestant + INCS |
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