TLDR: Some people with asthma may have respiratory reactions when they consume alcohol, such as chest tightness, rhinitis, and exacerbation of asthma symptoms. These reactions can be caused by allergens in the alcoholic beverages or by a genetic deficiency in metabolizing alcohol. Asians, particularly those of Japanese descent, are more susceptible to alcohol-induced respiratory reactions due to a specific genetic variant. Avoiding alcohol is the safest treatment, but certain medications may help alleviate symptoms.

Alcohol-induced respiratory reactions, also known as alcohol-induced asthma, are a type of bronchoconstriction response that can occur in individuals with asthma when they consume alcohol. These reactions can manifest as chest tightness, rhinitis (inflammation of the nasal passages), and exacerbation of asthma symptoms. It is important to note that these reactions are different from classical allergen-induced asthma triggered by inhalation of allergens.

The history of studying alcohol-induced respiratory reactions dates back to the 1970s when researchers observed that certain alcoholic beverages could provoke asthma symptoms in individuals with a history of asthma attacks. Further studies found that these reactions were induced by non-alcoholic allergens present in or contaminating the beverages. In some cases, alcohol itself was found to be the cause of asthmatic symptoms triggered by alcoholic beverages.

In Asians, particularly those of Japanese descent, alcohol-induced asthma reactions have been extensively studied. In these individuals, the ingestion of any alcoholic beverage or pure ethanol can lead to a range of symptoms, including an alcohol flush reaction (commonly known as the "Asian flush syndrome"), rapid heart rate, dizziness, urticaria (hives), systemic dermatitis, rhinitis, and exacerbation of asthmatic bronchoconstriction. These reactions are primarily attributed to a genetic deficiency in the metabolism of ethanol, specifically a variant allele of the ALDH2 gene.

The deficiency in acetaldehyde metabolism, caused by the glu487lys ALDH2 allele, leads to the accumulation of acetaldehyde in the blood and tissues. This accumulation triggers allergic-like symptoms by stimulating mast cells and basophils to release histamine. The prevalence of the glu487lys allele varies among different populations, with a higher occurrence in Asians compared to individuals of other ethnicities.

In non-Asians, alcohol-induced respiratory symptoms can also occur, although the underlying causes may differ. Some individuals may have gene-based abnormalities that result in the accumulation of acetaldehyde following alcohol consumption. Additionally, there may be a correlation between alcohol-induced rhinitis and asthma exacerbations and aspirin-exacerbated respiratory disease reactions.

Diagnosing alcohol-induced respiratory symptoms can involve survey questionnaires to determine the specific types of alcoholic beverages that trigger the reactions. Differentiation between allergic reactions to allergens in alcoholic beverages and acetaldehyde-induced genetic reactions can be done through medical tests, such as ethanol patch tests and genetic analysis.

The safest and most effective treatment for alcohol-induced respiratory reactions is to avoid consuming alcohol. This includes avoiding mouthwashes and medications that contain ethanol. H1 antagonists, a type of antihistamine, have been found to be effective in blocking bronchoconstriction responses to alcoholic beverages in individuals with alcohol-induced asthma. However, further research is needed to determine the best treatment approaches for different types of alcohol-induced respiratory reactions.

In summary, alcohol-induced respiratory reactions can occur in individuals with asthma when they consume alcohol. These reactions can be caused by allergens in the beverages or by genetic deficiencies in metabolizing alcohol. Asians, particularly those of Japanese descent, are more susceptible to these reactions due to a specific genetic variant. Avoiding alcohol is the safest treatment, but certain medications may help alleviate symptoms.