Mechanism and management of alcohol-induced asthma.

The purpose of the present review is to explain the mechanism of alcohol-induced asthma in Japanese. An oral ethanol provocation test was performed in Japanese asthmatics to measure pulmonary function, blood ethanol, acetaldehyde and histamine. Acetaldehyde dehydrogenase 2 (ALDH2) genotype was determined by polymerase chain reaction (PCR) and ethanol patch test. Human bronchi and mast cells were stimulated with acetaldehyde in vitro. Approximately half of the asthmatic subjects developed bronchoconstriction with concomitant increases in blood acetaldehyde and histamine, which was associated with genetically reduced ALDH2 activities. In vitro acetaldehyde stimulation induced bronchoconstriction and degranulation of human mast cells. Collectively, as a metabolite of alcohol, the elevation of acetaldehyde following alcohol consumption induces airway mast cells to release histamine, which result in exacerbation of asthma in susceptible population.