acutely life-threatening, 568 t by organ system, 570 t physiologic processes as, 567 t chronic, 566 differential diagnosis adolescents, 570 –571 infants, 568 –570 toddlers and preadolescents, 570 disposition, 571 evaluation and decision, 566 –567 algorithm, 569 f history, 566 , 567 f laboratory tests, 567 physical examination, 566 pathophysiology, 566 pediatric malnutrition and, 566 psychosocial factors of, 566 Werdnig–Hoffmann disease, 337 West Nile virus, 126 Wheals, 650 –651 Wheezing, 133 , 135 , 199 , 480 , 948 attributable to anaphylaxis, 573 cardiovascular abnormalities and, 573 –574 causes, 576 t clinical classification of, 573 t from congenital structural anomalies, 574 diagnostic approach, 575 f, 577 diagnostic tests, 576 –577 differential diagnosis, 572 –574 evaluation and decision history, 574 –575 physical examination, 575 –576 extrinsic tracheobronchial compression and, 574 pathophysiology, 572 persistent, 574 from pulmonary edema, 574 pulmonary hemorrhage and, 574