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Sinusitis

BASICS

  • Definition:
  • Acute sinusitis = symptomatic inflammation of ≥1 paranasal sinuses, <4 weeks duration, impaired drainage, obstruction, facial pain/pressure/fullness.
  • “Rhinosinusitis” preferred term (rhinitis & sinusitis usually coexist).
  • Subacute: 4–12 weeks.
  • Chronic: >12 weeks.
  • Recurrent acute: ≥4 annual episodes w/o persistent symptoms in between.
  • Uncomplicated = no extension beyond sinuses/nasal cavity.

EPIDEMIOLOGY

  • 1 in 8 adults in the US/year (~30 million)
  • 5th most common reason for antibiotics
  • Viral cause: 90–98% (bacterial 0.5–2%)
  • Peak: early fall–spring (URI season)
  • Most common diagnosis in family practice

ETIOLOGY & PATHOPHYSIOLOGY

  • Key mechanism: Sinus mucosal inflammation → ostia obstruction → impaired clearance → stagnation → bacterial growth
  • Causative agents:
  • Viral (majority): rhinovirus, influenza A/B, parainfluenza, RSV, adenovirus, coronavirus, enterovirus
  • Bacterial: Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis (most common)
    • More likely if:
    • Worsens >5–6 days after initial improvement
    • No improvement after 10 days

    • 3–4 days of fever >102°F with facial pain & purulent discharge

    • MRSA: rare (0–15.9%)
  • Fungal: Immunocompromised (aspergillus), nosocomial
  • Overdiagnosis/overuse of antibiotics → resistance

RISK FACTORS

  • Viral URI, allergic rhinitis, asthma
  • Smoking, dental infections/procedures
  • Anatomic: septal deviations, polyps, cleft palate, turbinate hypertrophy
  • Tonsillar/adenoid hypertrophy
  • Immunodeficiency (e.g., HIV, CF)
  • Prolonged supine positioning (ICU)

PREVENTION

  • Hand washing
  • Vaccination
  • Avoid symptomatic individuals, smoking, secondhand smoke

DIAGNOSIS

HISTORY

  • Symptoms predictive of bacterial sinusitis:
  • Worsening >5–6 days after improvement
  • Persistent ≥10 days
  • Persistent purulent discharge
  • Unilateral upper tooth/facial pain, maxillary tenderness
  • Fever
  • Associated: headache, congestion, retro-orbital pain, otalgia, hyposmia, halitosis, chronic cough
  • Urgent symptoms: visual changes (esp. diplopia), periorbital swelling/erythema, altered mental status

PHYSICAL EXAM

  • Fever, edema/erythema of nasal mucosa, purulent discharge
  • Sinus tenderness (esp. on bending forward)
  • Transillumination: confirms fluid if asymmetric
  • Pediatric: Sinuses develop by 20 y/o; kids: ~6–8 colds/year

DIFFERENTIAL DIAGNOSIS

  • Dental disease, CF, Wegener granulomatosis, HIV, neoplasm, nasal foreign body
  • Allergic rhinitis
  • Headache: tension, cluster, migraine

DIAGNOSTIC TESTS & INTERPRETATION

  • NOT routinely recommended.
  • Imaging: Not needed unless recurrent/failure of therapy/suspected complications (limited coronal CT)
  • Cultures/biopsy: chronic or fungal suspicion
  • Labs: Not needed for routine evaluation

TREATMENT

  • Most resolve with supportive care.
  • Antibiotics reserved for:
  • Symptoms >10 days
  • Severe onset (fever, purulent discharge, facial pain) for ≥3–4 consecutive days
  • Worsening after initial improvement

GENERAL MEASURES

  • Hydration, steam inhalation, saline irrigation (Neti pot/nasal drops)
  • Elevate head of bed, avoid caffeine/alcohol/smoke
  • Analgesics (acetaminophen, NSAIDs)

MEDICATION

First Line

  • Decongestants: pseudoephedrine, phenylephrine, oxymetazoline (max 3 days)
  • Intranasal steroids: budesonide, mometasone, fluticasone
  • Antibiotics: amoxicillin-clavulanate preferred; doxycycline alternative (adults)
  • Adults: 5–7 days; children: 10–14 days
  • TMP/SMX, 3rd gen cephalosporins: not recommended
  • Peds:
    • Amoxicillin (uncomplicated),
    • Amox-clav (severe/antibiotics/daycare),
    • Levofloxacin (severe PCN allergy),
    • Clindamycin + cefixime/cefpodoxime (nontype 1 PCN allergy),
    • Ceftriaxone IM (if can’t take oral)
  • Oral antihistamines: loratadine, cetirizine, fexofenadine, diphenhydramine, etc.
  • Leukotriene inhibitors: (e.g., montelukast) if asthma
  • Analgesics: as above

Second Line

  • Levofloxacin/moxifloxacin: for adults if no response
  • Change antibiotic class if failure after 72 hours

SPECIAL POPULATIONS

  • Pregnancy: saline, pseudoephedrine, most antihistamines, most nasal steroids safe
  • Amoxicillin, amox-clav, cephalosporins preferred antibiotics

ADDITIONAL THERAPIES

  • Topical ipratropium, guaifenesin
  • Surgery: for refractory cases or complications (FESS)
  • Hospitalization: for complications (meningitis, orbital cellulitis, abscess)

ONGOING CARE & PROGNOSIS

  • Return if no improvement in 72 hours or no resolution after 10 days of antibiotics
  • Most resolve within 10–14 days
  • Serious complications (meningitis, brain/orbital abscess, thrombosis) are rare

ICD-10

  • J01.41: Acute recurrent pansinusitis
  • J01.0: Acute maxillary sinusitis
  • J01.80: Other acute sinusitis

CLINICAL PEARLS

  • Most resolve with supportive care (pain, nasal symptoms).
  • Reserve antibiotics for symptoms >10 days or ≥3–4 days severe symptoms.
  • Newer antibiotics offer no benefit over amoxicillin or doxycycline.
  • Saline spray, drops, or irrigation (Neti pot) provide significant relief.