Paranasal sinuses: 1. frontal sinuses, 2. ethmoid sinuses (ethmoidal air cells), 3. sphenoid sinuses, 4. maxillary sinuses.
  • Viral source is by far most common. Bacterial infection accounts for only 0.5-2% of all cases[1]
    • Other causes include allergies and fungal infection
  • Timeframe
    • Acute (<4 weeks)
    • Subacute (4-12 weeks)
    • Chronic (>12 weeks)

Clinical Features

  • Defined as 2 or more of the following:
    • Blockage or congestion of nose
    • Facial pain or pressure
    • Hyposmia (diminished ability to smell)
    • Anterior or posterior nasal discharge lasting <12wk
  • Additional symptoms:
    • Tooth pain
    • Fever
    • Sinus pressure while bending forward to changing head position

Clinical Features of Bacterial Sinusitis

  • Symptoms persist >10 days
  • Daytime cough
  • Worsening or bimodal course
  • Fever >102.2F (39C)
  • Purulent nasal discharge >3d
  • Pain in maxillary teeth
  • Hx of diabetes

Clinical Features of Fungal Sinusitis

  • Seen most often in immunocompromised individuals and poorly controlled diabetics
  • Presents similarly to viral and bacterial sinusitis but symptoms worsen over time and do not improve with antibiotics
  • See Mucormycosis

Differential Diagnosis







Aseptic Meningitis


A CT scan showing sinusitis of the ethmoid sinus.
A CT scan showing sinusitis of the frontal sinus.
Maxillary sinusitis caused by a dental infection associated with periorbital cellulitis.
CT finding of chronic sinusitis.
  • Clinical diagnosis
  • Consider CT only for toxic patients (to rule-out complication)

IDSA Guidelines 2012[2]

  • Highlights identifying factors for acute bacterial vs. viral rhinosinusitis
  • Concern for bacterial (treat with antibiotics) if any of these:
    • Purulent discharge and pain on face or teeth > 10 days without improvement
    • Severe symptoms or fever > 39 plus symptoms > 3 days
    • "Double sickening" - sinusitis symptoms at end of initially improving URI that lasted > 5 days


<10 days of symptoms

>10 days of symptoms

  • Possible bacterial source, especially if associated with:
    • No clinical improvement after 10 days
    • Severe symptoms or high fever and purulent nasal discharge or facial pain lasting for at least 3–4 consecutive days at the beginning of illness
    • Onset with newly worsening that were initially improving (‘‘doublesickening’’)
  • Acute bacterial sinusitis[4]

Antibiotic Failure

  • Obtain culture
  • Consider nosocomial bacterial sinusitis (e.g. after prolonged nasotracheal intubation)
  • Consider foreign body
  • Consider antifungals


  • Discharge


See Also


  1. Fokkens WJ, Lund VJ, Mullol J, Bachert C, Alobid I, Baroody F, Cohen N, Cervin A, Douglas R, Gevaert P, Georgalas C, Goossens H, Harvey R, Hellings P, Hopkins C, Jones N, Joos G, Kalogjera L, Kern B, Kowalski M, Price D, Riechelmann H, Schlosser R, Senior B, Thomas M, Toskala E, Voegels R, Wang de Y, Wormald PJ. European Position Paper on Rhinosinusitis and Nasal Polyps 2012. Rhinol Suppl. 2012 Mar;(23):3 p preceding table of contents, 1-298
  2. Chow AW et al. IDSA clinical practice guideline for acute bacterial rhinosinusitis in children and adults. Clin Infect Disease (2012) 54:e72-112.
  3. Trestioreanu AZ, Yaphe J. "Intranasal steroids for acute sinusitis." The Cochrane Database of Systematic Reviews. 2 December 2013. DOI: 10.1002/14651858.CD005149.pub4
  4. Chow AW, Benninger MS, Brook I, et al. IDSA clinical practice guideline for acute bacterial rhinosinusitis in children and adults. IDSA Guidelines. 2012; Clinical Infectious Diseases e1-e41.