Statistical Analyses: Analysis will be done, using the Chi square statistic to determine the significance of the difference in proportion of the patients in each treatment group (antibiotic versus placebo) who sustain a complete resolution of their respiratory symptoms. A separate analysis will be done for children with persistent and non-persistent presentations. Analysis will also be done for each of the secondary outcome measures. For children enrolled in the trial, direct medical costs will be calculated and compared between treatment groups, including costs for antibiotic, hospitalizations, emergency room services, non-study related office visits, and antibiotics (other than the study medication), other medications prescribed and over-the counter medications used. Indirect medical costs will be assessed by comparing: