It is axiomatic in academic pediatrics that children with purulent rhinorrhea do not benefit from antibiotics unless: a) there are signs of severe paranasal sinusitis or b) the duration of cloudy tenacious nasal discharge exceeds nine days. Hypothesis: Is there CT evidence of paranasal sinus disease (effusion), particularly in the ethmoid sinuses, when purulent rhinorrhea has persisted for less than seven days. IRB approval was obtained prior to initiation of this study and written informed consent was obtained from parents of each subject. Children had to have at least 60 hours, but eight or fewer days of intermittent thick discolored purulent drainage, copious (5 c.c's or more) purulent material obtained by nasal douche, and at least 10 PMN's on a Wright stained preparation. Our lab used four-quadrant quantitative bacteriology (0.01 mL calibrated loop) on a droplet of nasal pus floating in saline effluent in a zip-lock bag. To be counted as a positive culture after overnight incubation, potential pathogens had to grow in at least the second quadrant of the agar plate and to far outnumber any background normal flora such as staph or non-group A strep species. On day one, multiple thin section CT coronal views of the maxillary and ethmoid sinuses and the osteomeatal complex were obtained without sedation on cooperative children. Only opacification/air fluid levels were considered as diagnostic of acute paranasal sinus effusion, thickening of the sinus mucosal lining was not precise enough. To date, 14 young children with no history of chronic rhinitis (mean age 7 years) have completed all study entry requirements, including CT scans. The mean duration of purulent rhinorrhea was only 3.9 days. Ten of the 14 (71%) had definite sinus effusion and seven had extensive ethmoid sinus involvement on CT. Only four patients lacked criteria for positive nasal wash culture for H. influenzae or S. pneumoniae. Children with acute copious purulent rhinorrhea usually have effusions (?infected) in their ethmoid or maxillary sinuses. The need to promote sinus drainage is self-evident. Funded by Glaxo, Inc.