Viral infection such as common cold is the most common cause of acute rhinosinusitis. Secondary bacterial infection during acute rhinosinusitis is relatively uncommon, estimated to be 0.5%–2% of adult cases. Despite this, antibiotics are frequently prescribed for patients presenting with symptoms of acute rhinosinusitis. So proper diagnosis of acute bacterial rhinosinusitis (ABRS) can help to reduce the excessive use of antibiotics. Hence two clinical practice guidelines have been proposed to provide the criteria for diagnosing ABRS; European Position Paper on Rhinosinusitis and Nasal Polyps (EPOS2012) and the Infectious Diseases Society of America clinical practice guideline for acute bacterial rhinosinusitis in children and adults (IDSA2012). (1, 2, 3, 4, 5)

AIM OF THE WORK:
The present research aimed to compare between two clinical practice guidelines: [EPOS2012, IDSA2012] in regard to the diagnostic accuracy for ABRS in terms of their sensitivity, specificity and predictive values.

PATIENTS AND METHODS:
The study had been conducted on a total number of 69 patients presented with symptoms suggestive of acute rhinosinusitis. All patients had been subjected to detailed history taking, full ENT clinical examination, temperature measurement provided that the patient had not received any antipyretic medications 6 hours before the measurement and investigations which included Serum C reactive protein (CRP), erythrocyte sedimentation rate (ERS) and middle meatal bacterial culture.