Clues to unrecognized upper airway obstruction.

A 24-year-old woman had virtually constant wheezing and shortness of breath unrelieved by inhaled or ingested bronchodilators. She reported that her "asthma" had begun following whooping cough in infancy, had abated during adolescence, then 9 years prior to admission had begun increasing after she was struck across the larynx. There was no family history of allergy and no personal history of eczema or atopic rhinitis. However, skin tests had disclosed cutaneous sensitivity to house dust, pollens, cotton and feathers; desensitization therapy had been ineffective. She had become pregnant 9 months before admission, and during the last trimester of pregnancy had noticed increasing difficulty with breathing. The patient's inspiration and expiration were prolonged and stridorous, and she spoke in a monotone. The stridor was detectable in the neck and anterior chest by auscultation. The results of chest roentgenography and routine blood