ARS Overview - Sinus Siege Starter
- Inflammation of nasal cavity & paranasal sinus mucosa.
- Types by duration:
- Acute Rhinosinusitis (ARS): < 4 weeks; symptoms resolve completely.
- Viral (AVRS): Common cold, typically < 10 days.
- Post-viral ARS: Symptoms worsen after 5 days or persist > 10 days.
- Acute Bacterial (ABRS): Often follows severe post-viral ARS.
- Recurrent Acute (RARS): ≥ 4 episodes/year; symptom-free intervals.
- Acute Rhinosinusitis (ARS): < 4 weeks; symptoms resolve completely.
- Affected sinuses: Maxillary, Ethmoid (anterior/posterior), Frontal, Sphenoid.
- Key drainage pathway: Ostiomeatal Complex (OMC).
⭐ Maxillary sinus is the most commonly affected sinus in adults.

Pathogenesis & Bugs - Nasty Nose Invaders
- Pathogenesis: Viral URI (commonest trigger) → mucosal inflammation → OsteoMeatal Complex (OMC) obstruction.
- Leads to: Impaired mucociliary clearance → secretion stasis → bacterial superinfection.
- Risk Factors: Allergic rhinitis, nasal polyps, septal deviation, dental infections, immunodeficiency.
- Common Bugs:
- Viral: Rhinovirus, Influenza.
- Bacterial (Acute Bacterial Rhinosinusitis - ABRS): 📌 S.M.H.
- Streptococcus pneumoniae (Most common)
- Haemophilus influenzae
- Moraxella catarrhalis
⭐ Obstruction of the Osteomeatal Complex (OMC) is pivotal for maxillary, frontal, and anterior ethmoid sinusitis.
Symptoms & Signs - The Snotty Story
- Major Criteria (Need ≥2):
- Nasal blockage/congestion
- Purulent nasal discharge (ant/post)
- Facial pain/pressure
- Hyposmia/anosmia (↓ smell)
- Minor Criteria (Supportive):
- Headache, fever, halitosis, fatigue, dental pain, cough, ear fullness/pain.
- Differentiating Features:
- Viral ARS: Symptoms <10 days, peak 3-5 days, then improve.
- Bacterial ARS: Symptoms >10 days OR "double sickening" (worsening after 5-7 days initial improvement) OR severe onset (fever ≥39°C + purulent discharge/facial pain for ≥3-4 consecutive days).
⭐ "Double sickening" (biphasic illness pattern) is a key indicator for bacterial rhinosinusitis.
Diagnosis, Dangers & Alerts - Spotting Sinus Storms
- Diagnosis (EPOS based): Sudden onset ≥2: nasal block/discharge, facial pain/pressure, ±anosmia. Duration < 12 wks.
- Viral ARS: Symptoms < 10 days, not worsening.
- Bacterial ARS (ABRS): ≥3 signs: discolored discharge (esp. unilateral) AND severe local pain (esp. unilateral); fever > 38°C; 📌 "Double Sickening" (worsening after initial improvement/5 days); ↑ESR/CRP.
- CT Scan: Not routine. Use for: suspected complications, severe/recurrent ARS, immunocompromised patients, pre-operative planning.

- ⚠️ Red Flags (Urgent Action!):
- Orbital: Proptosis, diplopia, ↓vision, ophthalmoplegia.
- Intracranial: Severe headache, altered mental status, meningism, focal neurological deficits.
- Other: Frontal swelling (Pott's puffy tumor), persistent high fever > 39°C, no improvement after 48-72h antibiotics.
⭐ Pott's Puffy Tumor: Frontal bone osteomyelitis with subperiosteal abscess. A critical complication of frontal sinusitis needing urgent surgery & IV antibiotics.
Treatment Toolkit - Blockage Busters
- Core Symptom Relief:
- Nasal saline irrigation.
- Analgesics (Paracetamol/NSAIDs).
- Decongestants: Oral; Topical (Oxymetazoline/Xylometazoline) for max 3-5 days. 📌 OXY-XYL for 3-5!
- Intranasal Corticosteroids (INCS): Fluticasone, Mometasone - cornerstone for ABRS.
- ABRS Antibiotic Choice:
- Amoxicillin (875mg BD) or Amoxicillin-Clavulanate (875/125mg BD).
- Penicillin allergy: Doxycycline or Respiratory Fluoroquinolone.
⭐ Amoxicillin-clavulanate is often preferred first-line for ABRS due to increasing resistance.
- Refer if: Severe symptoms, complications, no response to 2 antibiotic courses, or ≥4 episodes/year.
High‑Yield Points - ⚡ Biggest Takeaways
- Viral infections (Rhinovirus) are the primary cause of ARS.
- Bacterial superinfection typically involves S. pneumoniae, H. influenzae.
- Key symptoms: nasal obstruction, purulent discharge, facial pain/pressure, hyposmia.
- ARS < 4 weeks; bacterial if symptoms >10 days, severe, or double sickening.
- Orbital cellulitis is most common complication; Pott's puffy tumor (frontal sinusitis).
- Amoxicillin is first-line for uncomplicated bacterial ARS; consider Augmentin.
- Waters view for maxillary sinus; CT scan gold standard for complications/chronic ARS or suspected intracranial spread.
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