acute sinusitis

Introduction

Defined as inflammation of one or more of the paranasal sinuses, but generally refers to sinus infection. The maxillary sinuses are most frequently involved, either alone with involvement of the ethmoid &/or frontal sinuses. Sphenoid sinusitis is rare & is considered a medical emergency.

Etiology

• bacterial infection
  • Streptococcus pneumonia (35%)
  • Haemophilus influenzae (35%)
    • beta lactamase producing strains resistant to amoxicillin are uncommon in acute sinusitis
  • Streptococcus pyogenes & alpha-hemolytic Streptococci (10%)
  • Staphylococcus aureus (6%)
  • Moraxella catarrhalis (5%)
    • beta lactamase producing strains resistant to amoxicillin are uncommon in acute sinusitis
  • Eikenella corrodens
  • Chlamydia pneumoniae
  • Mycoplasma pneumoniae
  • anaerobes with polymicrobial infection (50%) in chronicsinusitis
• viruses (9%) {majority of cases}
  • rhinovirus
  • adenovirus
  • influenza virus
  • parainfluenza virus
• dental abscess
  • 5-10% of sinusitis
  • contiguous spread of bacteria
• hospitalized patients &/or nasopharyngeal intubation
  • gram negative bacilli (47%)
    • Pseudomonas
    • Acinetobacter
    • Escherichia coli
  • Staphylococcus (35%)
  • yeasts (18%) - more common in granulocytopenic patients

Predisposing factors:

• viral upper respiratory tract infection (URI)
  • most bacterial sinusitis occurs after an acute viral infection of the nasal mucosa
  • sinusitis occurs in 0.5% of patients with URI
• allergic rhinitis
• abuse of topical decongestants
• deviated nasal septum
• nasopharyngeal intubation (i.e. NG tube)
• nasal polyps
• tumors
• bronchiectasis
• immunodeficiency
• strong association with asthma

Pathology

• obstruction of sinus drainage into the nasal cavity
  • inflammation
  • edema
• decreased ciliary action
• increased mucus production
• diminished oxygenation of sinus cavity
• proliferation of anaerobic & facultatively anaerobic bacteria
• impairment of neutrophil function
• decreased immunoglobulin production
• sinusitis is an important trigger for asthma

Clinical manifestations

• major criteria*
  • mucopurulent or purulent nasal discharge
  • purulent pharyngeal drainage
• minor criteria*
  • periorbital edema
  • headache
  • facial pain/tenderness, may be unilateral
    • facial tenderness most useful in frontal sinusitis
    • pain exacerbated by bending over or with head movement
  • maxillary toothache (pain in upper teeth)
  • earache
  • sore throat
  • hallitosis
  • increased wheeze
  • fever
• other
  • generally patient does not appear very ill
  • afebrile or low-grade fever
  • nasal congestion, cough
  • poor response to over-the-counter nasal decongestants & antihistamines
  • abnormal transillumination
    • neither sensitive nor specific
    • generally requires complete opacification
  • ethmoidal sinusitis
    • relieved by maintaining head upright
    • exacerbated by lying supine
  • maxillary sinusitis
    • relieved by lying supine
    • exacerbated by the head in an upright position
  • sphenoidal sinusitis
    • pain or tenderness over the occiput or vertex of the skull
  • symptoms of upper respiratory tract infection uncommon
  • 2 or 3 of: upper respiratory tract infection > 7 days, facial pain, purulent discharge yields > 50% likelihood of sinusitis
• red flags
  • patient appears acutely ill
  • fever
  • periorbital edema
  • neurologic signs

* 2 major criteria or 1 major & 2 minor criteria indicates probable sinusitis

Diagnostic criteria

acute bacterial sinusitis

• persistent symptoms lasting at least 10 days, without improvement
• severe symptoms or high fever & purulent nasal discharge or facial pain for 3-4 days at onset of illness
• worsening symptoms after an initial respiratory infection, lasting 5-6 days, has started to improve

Laboratory

• generally sinusitis is a clinical diagnosis
• sinus aspiration & culture is gold standard
  • useful for guiding antibiotic coverage in refractory sinusitis
• culture of nasal secretions is useless

Diagnostic procedures

• endoscopy
  • sinus aspiration & culture
  • useful for draining sinus

Radiology

• imaging not routinely recommended
  • treat empirically
  • immunocompromised patients may be exception
• conventional radiographs
  • useful for confirming acute maxillary sinusitis
    • Water's view
    • 4 view sinus series
    • opacification, air-fluid level or thickened mucosa filling > 50% of antrum
  • poor visualization of ethmoid sinuses
• computed tomography (coronal sinus CT)
  • visualization of ethmoid sinuses
  • 90-100% sensitivity, 60% specificity
  • method of choice
• magnetic resonance imaging

Complications

• subdural & cerebral abscess
• orbital cellulitis via spread from ethmoid sinusitis
• osteomyelitis
• meningitis
• cavernous sinus thrombosis

Differential diagnosis

• inflammatory
  • allergic rhinitis (common)
  • viral rhinitis (common)
  • nasal polyps
  • Wegener's granulomatosis
  • sarcoidosis
• non-inflammatory
  • idiopathic vasomotor rhinitis (common)
  • drug-induced vasomotor rhinitis
    • reserpine
    • guanethidine
    • prazosin
    • ACE-inhibitors
    • cocaine
  • rhinitis medicamentosa (common)
  • hormonal
    • pregnancy
    • hypothyroidism
• mechanical
  • deviated nasal septum (common)
  • nasal polyps
  • tumor
  • foreign body
• other disorders with sinus involvement
  • Kartagener's syndrome
  • bronchiectasis
  • cystic fibrosis
  • chronic bronchitis
  • asthma
• migraine

Management

• non-pharmaceutical measures:
  • drink plenty of fluids
  • adequate rest & sleep
  • inhaling steam may ease congestion of sinuses
  • consider other diagnoses
• pharmaceutical agents
  • symptomatic relief with topical decongestants, intranasal corticosteroids & antihistamines
  • decongestants
    • no evidence of benefit; appropriate
    • oxymetazoline (Afrin) nasal spray BID for 3-5 days
      • interferes with healing of maxillary sinusitis by decreasing nasal mucosal blood flow
    • phenylephrine (Neo-Synephrine)
      • 2-3 sprays every 4 hours for 5 days
      • preferred agent
    • pseudoephedrine (Sudafed) 120 mg PO BID
  • nasal corticosteroids
    • limited role in acute sinusitis
    • useful for treatment of allergic rhinitis
    • may be useful for persistent rhinosinusitis
    • no benefit of systemic corticosteroids
  • antihistamines
    • thicken secretions, non-sedating antihistamines are less likely to thicken secretions
    • not indicated in treatment of acute sinusitis
      • ref advocates use of antihistamines
    • useful for treatment of allergic rhinitis
  • mucolytic agents - guaifenesin 30 mL QID
  • inhalation of steam
  • nasal saline
  • antibiotics
    • indications: see diagnostic criteria
    • amoxicillin or amoxicillin clavulanate (Augmentin) for 5-10 days for acute bacterial sinusitis (1st line)
      • amoxicillin less effective amoxicillin clavulanate (Augmentin) due to resistance of Haemophilus influenzae & Moraxella
      • penicillin or amoxicillin as effective & associated with fewer adverse events than amoxicillin clavulanate or cephalosporins in children
    • Bactrim or macrolides not recommended because of high rates of antimicrobial resistance
    • if Haemophilus or Moraxella suspected
      • Augmentin
      • 2nd generation cephalosporins
        • cefaclor (Ceclor)
        • cefuroxime (Ceftin)
        • loracarbef (Lorabid)
        • cefpodoxime (Vantin)
      • azithromycin (Zithromax)
      • fluoroquinolone
        • levofloxacin, moxifloxacin or gatifloxacin
        • avoid older fluoroquinolones (ciprofloxacin, ofloxacin); NOT effective against pneumococcus
    • if prior antibiotic use, ceftriaxone or fluoroquinolone
    • duration of therapy: 5-7 days
      • levofloxacin 750 mg QD for 5 days (Leva-pak)
      • older guidelines of 10-14 days commonly followed
    • antibiotics not useful; useful in children
    • amoxicillin 500 mg PO TID no better than placebo
    • number needed to treat (NNT) with antibiotics for faster resolution = 15-18; number needed to harm = 8 for medication adverse effects (diarrhea, vomiting, skin rash)
    • antifungal agents may be useful in cases of allergic fungal sinusitis with polyposis
• patient education
  • most patient feel subjective improvement after 5-6 days of effective therapy
  • prolonged use of topical decongestants may cause rebound vasodilation with worsening of symptoms
  • avoidance of allergens in patients with underlying allergies
• indications for referral to otolaryngologist
  • patients not improving with therapy
  • recurrent sinusitis
  • acute invasive fungal sinusitis requires hospitalization & surgery

More general terms

• sinusitis
• acute inflammation
• acute upper respiratory tract infection

More specific terms

• acute ethmoidal sinusitis
• acute frontal sinusitis
• acute maxillary sinusitis
• acute rhinosinusitis
• acute sphenoidal sinusitis

Additional terms

• paranasal sinus

Patient information

acute sinusitis patient information