Recurrent nocturnal near fatal asthma in a young man.

A young man who suffered multiple near fatal nocturnal asthmatic attacks, including at least three episodes of respiratory arrest, was found to be symptomatically unaware of marked increases in airway obstruction, and failed to perceive bronchoconstriction induced by methacholine challenge. Intensive antiasthma treatment monitored by regular peak expiratory flow measurements abolished the nocturnal attacks, which recurred twice when treatment lapsed. Patients prone to apparently sudden and life-threatening attacks of asthma may be at risk because of failure to perceive steadily worsening asthma.