For infants, a history of prematurity, mechanical ventilation (tracheal stenosis), or noisy breathing independent of symptoms of respiratory infection may suggest either bronchopulmonary dysplasia or a congenital structural airway abnormality. Investigate all perinatal screening to assess for HIV status of mother and child and pulmonary or cardiac anatomic anomaly that may have been seen on ultrasound. Delayed passage of meconium may be a clue for cystic fibrosis. Reflux, arching, or choking above the ordinary could be a sign that gastroesophageal reflux disease (GERD) or aspiration are a cause of wheezing. A history of sweating and/or difficulty with feeds suggests congenital heart disease and cardiac failure. Family history of asthma, cystic fibrosis, α1-antrypsin deficiency, immunodeficiency, or immotile cilia/Kartagener syndrome would be of interest. Relevant social history includes exposure to smoke or other exhaust, pets or animals, daycare, or travel. If tuberculosis is being considered, evaluate risk factors for exposure, including foreign travel, contact with visitors from other countries, or contact with prisoners or homeless shelters. Unusual causes of wheezing, such as histoplasmosis or other endemic fungi are more likely to occur after travel to the mid-Atlantic.