Acute Rhinosinusitis Treatment: Distinguishing from Chronic Sinusitis

Rhinosinusitis: inflammation of nasal and paranasal sinus mucosa. The older "sinusitis" gave way to modern "rhinosinusitis" — nose and sinuses function as a unit (mucociliary transport, airflow, immune response).

Duration-based classification: acute rhinosinusitis (ARS) <4 weeks, subacute 4-12 weeks, chronic rhinosinusitis (CRS) ≥12 weeks, recurrent acute ≥4 episodes/year (each fully resolved between).

Aetiology: viral (most common — common cold, most ARS); bacterial (around 2% of ARS); fungal (immunocompromised — acute invasive; immunocompetent — allergic fungal sinusitis); rare — anatomic, autoimmune, granulomatous (Wegener), neoplastic.

EPOS (European Position Paper on Rhinosinusitis and Nasal Polyps) is the current gold standard classification. ARS: at least 2 of 4 cardinal symptoms (nasal obstruction, anterior/posterior nasal discharge, facial pain/pressure, hyposmia) lasting <12 weeks. CRS: same symptoms ≥12 weeks + endoscopic or CT finding (polyp, purulent discharge, oedema, ostiomeatal complex narrowing).

Anatomy: maxillary (largest, most often involved), ethmoidal (mid, multiple small cells), frontal (forehead), sphenoidal (posterior, deep). Drainage: maxillary, anterior ethmoid, frontal → middle meatus (ostiomeatal complex); posterior ethmoid → superior meatus; sphenoid → sphenoethmoidal recess.

ARS prevalence: adults 5-15% annually; children more often (5-10% of upper respiratory tract infections develop into ARS). CRS prevalence in adult European populations 10-12%; Turkish data similar.

Risk factors: allergic rhinitis (CRS risk 3-5×), asthma (shared inflammation with CRS — unified airway concept), smoking, anatomic anomalies (septal deviation, concha bullosa), immunosuppression (HIV, transplant, chemotherapy), cystic fibrosis, primary ciliary dyskinesia, GERD, upper dental infection (odontogenic maxillary sinusitis). We expand on the clinical framework in our general ENT services.

Diagnosis is clinical — imaging not routinely needed. History and examination suffice. Imaging only for suspected complication, atypical picture, or treatment failure.

Clinical picture: prodrome — nasal obstruction, discharge, sneezing, malaise (general viral URTI); after 3-5 days sinuses become involved — facial pain/pressure (worse on leaning), purulent discharge, headache, hyposmia. Most patients recover within 7-10 days.

Viral vs bacterial ARS distinction is critical. EPOS 2020 / IDSA 2012 bacterial ARS criteria: (1) symptoms ≥10 days without improvement — viral usually resolves within 7-10 days; (2) "double sickening" — initial viral pattern with improvement at 4-5 days, then recurrence + new or worsening symptoms (high fever, more intense facial pain, more purulent discharge); (3) severe onset — high fever (>38.3°C) + severe facial pain + purulent discharge sustained 3-4 days.

Bacterial ARS pathogens: Streptococcus pneumoniae (25-35%), Haemophilus influenzae (25-35%), Moraxella catarrhalis (in children — 10-15%), rare — anaerobes (odontogenic), Staphylococcus aureus.

First-line antibiotic: amoxicillin-clavulanate 875/125 mg twice daily, 5-7 days. Plain amoxicillin alone is inadequate given rising resistance. Penicillin allergy (true type I): doxycycline 100 mg twice daily or trimethoprim-sulfamethoxazole; fluoroquinolone (levofloxacin, moxifloxacin) last choice (side effects + resistance).

Antibiotic duration: 5-7 days sufficient (older 10-14 days recommendations revised). Improvement usually begins by day 2-3; if symptoms persist beyond completion, extend 5-7 days or switch antibiotic.

Treatment failure: no improvement after 3-5 days → imaging (CT), ENT consult, resistant organism investigation. CT findings: mucosal thickening (≥4 mm significant), fluid level, opacification, ostiomeatal complex narrowing, bone destruction (osteomyelitis, invasive fungal).

Anti-inflammatory treatment: topical intranasal corticosteroid (mometasone, fluticasone, budesonide) reduces inflammation and duration in ARS — evidence available (Cochrane analyses). Does not replace antibiotic when bacterial. Saline irrigation (large volume — Neti pot, squeeze bottle) mechanically cleans + improves mucociliary transport.

Oral steroid: short-course (3-5 days) considered in high symptom burden, polypoid oedema; not routine. Side effects (weight, bone, blood sugar, AVN risk) to be considered.

Complication signs — EMERGENCY: orbital cellulitis (peri-orbital swelling, redness, pain, diplopia, proptosis, vision loss), cavernous sinus thrombosis (ophthalmoplegia, bilateral eye involvement, altered mental status), intracranial abscess (high fever, severe headache, focal neurology, altered mental status), meningitis (neck stiffness, photophobia, fever). These require IV antibiotic + surgical consult + imaging.

CRS (chronic rhinosinusitis) is a very different disease from ARS — chronic inflammatory process, usually non-bacterial aetiology, completely different management. Misinterpretation (CRS treated as recurrent ARS) leads to inappropriate antibiotic use.

CRS criteria (EPOS 2020): symptoms ≥12 weeks (nasal obstruction, discharge, facial pain/pressure, hyposmia — at least 2) + endoscopic finding (polyp, purulent middle meatus discharge, oedema/obstruction) or CT finding (mucosal disease ostiomeatal or sinuses).

CRS classification: CRSwNP (with nasal polyposis — about 25-30% — more eosinophilic), CRSsNP (without polyps — more neutrophilic). Distinction affects therapy.

CRS pathophysiology: Type 2 (Th2) inflammation — IL-4, IL-5, IL-13, eosinophilia, IgE; allergy + asthma + atopic dermatitis (atopic triad) association. Bacterial or viral acute exacerbation is secondary; the core is mucosal inflammation and oedema.

Treatment (CRSsNP): first line large-volume saline irrigation (daily Neti pot), topical intranasal corticosteroid (mometasone, fluticasone, budesonide — daily, long term), oral antibiotic generally not needed. Refractory: macrolide (clarithromycin, azithromycin — low-dose long-term for anti-inflammatory effect), oral steroid short bursts.

Treatment (CRSwNP): topical steroid + short-course oral steroid (high dose) for polyps; surgery (FESS — functional endoscopic sinus surgery) for refractory — polyp resection + ostiomeatal complex widening + better topical steroid penetration. New biologics: dupilumab (IL-4/IL-13), omalizumab (anti-IgE), mepolizumab (anti-IL-5) — effective in refractory CRSwNP; high cost.

Surgery (FESS): indicated when CRS refractory (medical therapy fails 3-6 months). Endoscopic approach opens ostiomeatal complex, restores ventilation and drainage + post-op topical steroid penetration improves. Success 80-90% CRSsNP, 70-80% CRSwNP.

Antibiotics in CRS? In acute exacerbation (significant worsening, fever, purulent discharge) and post-surgical infection prevention; routine chronic antibiotic (systemic) not recommended — resistance + side effects + limited benefit. Topical antibiotic (mupirocin rinsing) used in some protocols — evidence limited.

ARS vs CRS practical distinction: ARS symptoms <12 weeks, single episode, often post-viral URTI; CRS symptoms ≥12 weeks, persistent, often allergy/asthma comorbidity, endoscopic or CT finding required. A CRS patient may have ARS exacerbations — exacerbation may need antibiotics, the CRS background therapy (topical steroid) is maintained. More detail: sinusitis page.

Most acute rhinosinusitis self-resolves; home symptom management suffices. Do not consider antibiotic in first 7-10 days — viral process.

Home management: (1) saline nasal irrigation — Neti pot, squeeze bottle, isotonic or hypertonic saline (3%) 2-4× daily large volume. Removes mucus + crusts + improves mucociliary transport. Use distilled or boiled water (tap water has amoeba risk!); (2) steam inhalation — warm steam thins mucus, eases drainage; 2-3× daily 10-15 minutes; eucalyptus or menthol additive (symptomatic); (3) hydration — plenty fluids (water, soup, tea) — mucus thinning; (4) head elevation (when sleeping) — improves drainage; (5) analgesic — paracetamol 500-1000 mg every 6 hours, ibuprofen 400 mg every 6-8 hours — for pain + facial pressure.

Topical nasal steroid (over-the-counter or prescription): mometasone, fluticasone, triamcinolone. 1-2 sprays per nostril daily for 7-14 days. Reduces inflammation, hastens symptom resolution. Long-term in CRS.

Topical decongestant (oxymetazoline — Iliadin spray): short-term use, max 3-5 days. Rhinitis medicamentosa — rebound dependency + persistent congestion if prolonged. Short use acceptable for acute symptom control.

Oral decongestant (pseudoephedrine — Sudafed): reduces mucosal swelling; short-term. Side effects: raised BP, palpitations, insomnia, urinary retention in older men. Contraindicated in hypertension, pregnancy, cardiac disease.

Antihistamines: limited benefit in viral ARS; useful when allergic rhinitis coexists (year-round or seasonal).

When to see a doctor? (1) symptoms ≥10 days without improvement; (2) "double sickening" — worsening after initial improvement; (3) high fever (>38.3°C) + intense facial pain/purulent discharge 3-4 days; (4) recurrent sinusitis (≥4 episodes/year); (5) chronic (≥12 weeks) symptoms; (6) complication signs — periorbital swelling/redness, vision change, altered mental status, neck stiffness, severe headache (EMERGENCY).

Prevention: allergic rhinitis management (trigger ID + avoidance + immunotherapy), smoking cessation, hydration, saline irrigation (in allergic or dry-climate weekly), vaccines (annual flu, COVID, S. pneumoniae), reduce second-hand smoke, evaluate anatomic anomaly (septal deviation — if symptomatic consider surgery).

Smoking and ARS: smoking impairs mucociliary transport, increases ARS risk and duration. Active and passive both. Cessation reduces ARS prevalence and recurrence. We share patient experiences on our Istanbul ENT services.