Functional upper airway obstruction and chronic irritation of the larynx.

Wheezing and dyspnoea are typical symptoms of asthma but can also be found in diseases of the extrathoracic airways. Functional upper airway obstruction may imitate, as well as complicate asthma. Functional upper airway obstruction was first described as a conversion disorder in young females with inspiratory stridor. Subsequently, it was found that functional upper airway obstruction was more often a secondary phenomenon in chronic asthma also involving the expiratory laryngeal airflow. During a period of 15 months, we diagnosed six cases of functional upper airway obstruction. Five patients were female and one male, and four were also asthmatics. Three cases showed chronic sinusitis with postnasal drip (PND) and/or gastro-oesophageal reflux. Both disorders may irritate the larynx. Treatment of sinusitis and gastro-oesophageal reflux led to a significant improvement of dyspnoea in all three of these patients. In asthma refractory to treatment and in the case of an asthmatic exacerbation without obvious cause, functional upper airway obstruction should be excluded to avoid unnecessary treatment with systemic steroids. Some of the possible causative factors of functional upper airway obstruction, such as postnasal drip and gastro-oesophageal reflux, are easily treatable.