It\'s rare, but allergies to alcohol can cause symptoms such as red itchy eyes, nasal congestion, upset stomach and breathing problems, U.S. researchers say. Allergist Dr. Sami Bahna, chief of allergy and immunology at Louisiana State University Medical School in Shreveport, said reactions can be triggered by naturally occurring ingredients in beer and wine, including barley, ethanol, grapes, histamine, hops, malt, oats, tryptamine, tyramine, wheat and yeast. Other potential allergens may be introduced to beer and wine during processing, including egg whites, which are sometimes used as a filtering agent and sulfites, which occur naturally in wine but also may be added as a preservative, Bahna said. In most cases, simply understanding what triggers the allergic reaction will help the person find an alternative drink to enjoy, Bahna said in a statement. \"Individuals can be allergic to the alcohol itself or an added ingredient, but even when people are not allergic, they may not realize that alcohol can worsen existing allergy symptoms, particularly food allergies.\" Allergic reactions to alcohol can produce minor symptoms such as rash, or life-threatening reactions including asthma attacks and anaphylaxis, Bahna said. Wine, particularly red wine, contains chemicals called tyramines that commonly cause headache, Bahna added. Bahna presented his findings at the annual scientific meeting of the American College of Allergy, Asthma and Immunology in Boston.