Laryngeal dysfunction: a common cause of respiratory distress, often misdiagnosed as asthma and responsive to antireflux therapy.

Asthma is diagnosed frequently in patients with respiratory distress. However, laryngeal dysfunction, a common cause of dyspnea, may masquerade as asthma. This study investigated 158 consecutive patients referred to an allergy practice with a diagnosis of asthma. Pulmonary function testing with flow volume loops were used to separate the patients into four groups. These groups consisted of patients with asthma alone in 32%, asthma and laryngeal dysfunction in 16%, laryngeal dysfunction in 26%, and another group not meeting these criteria in 25%. Thirty patients, 10 each from the first three groups, were treated with antireflux medication and reevaluated. Symptom evaluation observed inspiratory difficulties in 73% of the laryngeal dysfunction group compared with 2% of the asthma group (p < 0.0001). Expiratory problems were present in 7% of the laryngeal dysfunction group and 71% of the asthma group (p < 0.0001). The laryngeal dysfunction group only had a 29% beneficial response to Albuterol inhalation compared with a 92% response in the asthma group (p < 0.0001). The laryngeal dysfunction group responded significantly less to both inhaled and oral steroids (p = 0.002). Among the 30 patients treated with antireflux medications, the peak flows improved by 38.7% in the laryngeal dysfunction group compared with 14.8% in the asthma group (p = 0.01).