Up to 15 million Americans have food allergies with reactions ranging from swelling and vomiting to death, according to the Food Allergy & Anaphylaxis Network. Food allergies break down along eight major groups: milk, egg, peanut, tree nut, fish, shellfish, soy and wheat. Most dairy allergies begin and end in the early years of life, though some adults have allergies to milk-based products, including yogurt, according to the network.

Is This an Emergency?

If you are experiencing serious medical symptoms, seek emergency treatment immediately.

Symptoms and Diagnosis

Only a certified allergist or immunologist can make a definitive diagnosis of food allergy, but symptoms are easy to detect. When an allergic child encounters yogurt or another dairy product, the food's enzymes trigger a negative reaction. In mild reactions, this may include swelling of the skin, hives or digestive distress like vomiting, cramps or diarrhea. In severe cases, according to the American Academy of Allergy Asthma & Immunology, a person can go into anaphylactic shock 1. This causes throat or chest tightness, inability to breathe and tingling in the extremities, lips and scalp. Allergists and immunologists will run skin-contact tests and blood tests to determine whether a component of yogurt -- such as dairy, live bacteria or enzymes, or any added artificial or natural flavors -- causes the reaction.

Treating Yogurt Allergies

Once the doctor determines the allergy's cause, she will counsel you to remove it from your diet. While some allergies, like environmental or dust reactions, can be treated with medication, the only way to control a food allergy is to cut the trigger from your diet. According to doctors at Michigan Allergy Sinus & Asthma Specialists, allergy injections are not effective in treating food allergies 1.

Histamine-Rich Foods

The body produces histamine as a response to allergens. This enzyme causes your eyes to water or nose to run when you encounter an allergen. Histamine is also present in yogurt. A person eating yogurt who begins to complain of itchy or watery eyes, hives, itchy skin or nose, wheezing, diarrhea or headaches may not have a yogurt allergy, but might be reacting to histamine's introduction to the body. Yeast added during yogurt's fermentation process creates the histamine, according to Michigan Allergy, Sinus and Asthma Specialists.

Fish or Nut Allergy

The type of yogurt you eat is just as important as the yogurt itself. Many companies have introduced heart-healthy varieties of yogurt containing omega-3 fatty acids derived from fish or nuts. Omega-3 fatty acids are antioxidants, which protect cells from mutation and damage. Check the ingredients label for fish oil or alpha-linoleic acid, which can trigger fish allergies, or references to nuts. Omega-3 derived from algae or flaxseed should be allergen-free, states the Allergy & Asthma Network.

Lactose Intolerance

Lactose intolerance often is mistaken for an allergy to yogurt and other dairy items, but it is actually a digestive issue. When yogurt is digested, a natural sugar called lactose is released into digestive track. The body makes an enzyme called lactase to break down the lactose so the body may absorb it, according to the National Digestive Diseases Information Clearinghouse. People who cannot produce lactase are lactose intolerant but not allergic to yogurt or other dairy products.