Common bacterial pneumonitis in infants. Determining the etiology and tailoring the treatment.

In infantile pneumonia, we recommend close attention to the history and physical examination. Baseline studies, including CBC, ESR, blood cultures, and chest film, should be performed at onset and repeated as warranted. Nasopharyngeal secretions or washings should be drawn by means of gentle suction and specimens sent for Gram stain, fluorescent antibody stain for respiratory syncytial virus, and culture for bacteria and for viruses if possible. Acute and convalescent serum specimens should be obtained in serious cases to search for antibodies to RSV, adenovirus, influenza, parainfluenza, cytomegalovirus, and Chlamydia. Serum and urine specimens may be collected for countercurrent immunoelectrophoresis and latex agglutination testing for Hemophilus influenzae type B, Streptococcus pneumoniae, and if indicated, group B streptococcus. If deterioration continues and all tests are negative, the clinician should consider a more invasive procedure such as flexible fiberoptic bronchoscopy, needle aspiration, or open lung biopsy. While awaiting identification of the pathogen, the physician should institute empiric therapy with optimum doses of antimicrobials and monitoring of serum levels of drug. Often the clinician is faced with deterioration and a negative workup. In this situation, other agents may be added, such as antifungal, antiviral, antiprotozoan, and antituberculous agents, as well as various antibiotics, to cover rare and unusual pathogens. Further consultation, even by phone, may at this point provide some insight into an otherwise confusing case.