The implication of the DAO deficiency in allergies, together with the intolerance to sulphites, are a cause of asthma in people who suffer from both syndromes, and even more when them consume alcoholic drinks like champagne or wine.
There are two possible mechanisms
by which the consumption of wine or champagne can produce asthma: intolerance to sulphites
(sulphites are preservatives in the series E-220 to E-228, present in the wine, beer and champagne, and are metabolized by the enzyme sulfite oxidase, so that a deficit in this enzyme causes its intolerance) and the blocking or deficit of the DAO enzyme
(the enzyme diamine oxidase), which activity is blocked by the presence of alcohol.