What Is a Yogurt Allergy?

If you find yourself breaking out in hives or rushing to the bathroom after eating yogurt, you may feel like you have a yogurt allergy. A yogurt allergy is also known as a milk allergy because it is a food that is produced by the bacterial fermentation of milk.

However, in some cases, feeling unwell after yogurt consumption could be caused by lactose intolerance or other conditions that can produce similar symptoms.

This article will discuss the potential causes of a yogurt allergy, including lactose intolerance and different types of milk allergies, how to treat these conditions, and alternatives to try.

What Is a Milk or Yogurt Allergy

A milk allergy is one of the most common food allergies in children. An estimated 2 to 3 out of every 100 children have an allergy linked to cow's milk. While many children outgrow a milk allergy, it can sometimes persist well into adulthood.

Cow's milk allergy, also called cow's milk protein allergy, is an abnormal response by the immune system to the proteins found in cow's milk. The two main types of milk protein that cause a milk allergy are casein and whey.

Causes of Milk Allergy

Milk allergies are often caused by an immune system malfunction. When a person with a true milk allergy consumes foods with milk in them, such as yogurt, their immune system mistakes them as being a harmful invader. This triggers the production of immunoglobulin (IgE) antibodies, which leads to the release of chemicals, causing an allergic reaction. If you have a milk allergy, you may be allergic to the proteins in the milk, which include:

• Whey proteins are found in the lactose-containing liquid part of the milk. It makes up about 80% of milk protein. The two proteins found in whey are called alpha-lactalbumin and beta-lactalbumin. While it is found in cow's milk, whey protein may also be present in other products such as sports drinks, protein powder, yogurt, and cheese. It is one of the proteins found in milk tied to more serious reactions.
• Casein is the solid part of the milk that curdles. It is a protein found in milk and dairy products and many non-dairy products such as tuna and sausage. A newer blood test called a component test can check for both casein and whey allergies.
• Food protein-induced enterocolitis syndrome (FPIES) is a type of non-IgE mediated food allergy. It is rare and mainly affects young children and babies. Similar to other food allergies, it involves a reaction to a certain food. Common trigger foods include soy, cow's milk, and grains. Fortunately, most children outgrow this allergy by the age of 4.
  

Risk Factors for Milk Allergy

Certain factors may increase the risk of developing a cow's milk allergy, including:

• Other allergies: A person with other underlying allergies is more at risk of developing other allergies, such as a milk allergy.
• Genetics: Having parents and siblings with food allergies can put you at a higher risk of developing a milk allergy.
• Age: Milk allergies are most common in children, and many of them outgrow them as their digestive tract matures.
• Atopic dermatitis: Although the exact reason is not fully understood, children with atopic dermatitis are more likely to develop a food allergy.
  

Milk Allergy Symptoms

The symptoms of a milk allergy can range from mild to severe and usually occur within two hours of drinking milk.

Milk allergy symptoms include:

• Hives
• Upset stomach
• Diarrhea
• Vomiting
• Bloody stools
• Abdominal pain

Unexpected Sources of Milk Proteins

Many people with a milk allergy also do not tolerate milk from other domestic animals like goats or sheep. It's important to always read your food labels and avoid any ingredients that contain milk.

Some unexpected sources of milk proteins include:

• Tuna
• Butter
• Pudding
• Custard
• Cereal
• Pancakes
• Luncheon meat
• Some non-dairy products
• Chocolate
• Caramel candies
• Bodybuilding shakes

Treatment for Milk Allergy

Avoiding milk, dairy, or products that contain milk protein is the best way to treat a milk allergy.

For mild reactions, your healthcare provider may suggest taking an over-the-counter antihistamine. If you have a severe milk allergy, it's important to keep an epinephrine auto-injector (EpiPen) with you at all times. Epinephrine is the only treatment for anaphylactic shock.

Lactose Intolerance

Lactose intolerance occurs when a person is missing the enzyme lactase, a sugar found in milk and milk products like cheese, yogurt, or ice cream. It is responsible for breaking down the lactose you eat and drink. As a result, a person with lactose intolerance cannot digest foods containing lactose without discomfort.

True Milk Allergy vs. Milk Intolerance

A true milk allergy is not the same as a milk intolerance. A milk allergy happens when your immune system identifies milk and milk products as foreign invaders. This causes hives, nausea, abdominal pain and can even lead to anaphylactic shock.

In contrast, milk intolerance is more digestive in nature and does not involve the immune system. A person who has milk intolerance is missing the enzyme lactase. Because they are missing this enzyme, they are unable to digest foods containing lactose. This leads to abdominal pain, cramps, or diarrhea.

Causes of Lactose Intolerance

Lactose intolerance is often caused by lactose malabsorption, a condition in which your small intestine makes low levels of lactase.

In some cases, your genes may also play a role in the development of lactose intolerance. It may also be caused by premature birth or damage to your small intestines that occurs with Chron’s or celiac disease.

Signs of Lactose Intolerance

Without proper digestion, the lactose passes to your colon, where bacteria break down the lactose and create fluid and gas, which is responsible for digestive discomfort.

Other signs of lactose intolerance include:

• Bloating
• Gas
• Diarrhea
• Nausea
• Abdominal pain

Risk Factors for Lactose Intolerance

If you come from a part of the world where malabsorption is common, you are at a higher risk for lactose intolerance. In the United States, the following racial and ethnic groups are at a higher risk for lactose intolerance:

• African Americans
• Asian Americans
• American Indians
• Hispanics

Alternatives

People with lactose intolerance can sometimes handle small amounts of lactose. Some studies show that many people can tolerate around 12 grams of lactose with very little or no symptoms. This is equivalent to about 1 cup of milk. 

Additionally, some people can tolerate low-lactose foods like yogurt and hard cheeses such as Swiss and cheddar. You can also use lactase products to help your body digest the lactose in milk.

Treating Lactose Intolerance Symptoms

Some people need to eliminate lactose altogether for symptom relief while others can cut back on the amount they consume.

Alternatively, you can take lactase products before consuming milk or milk products. This helps your body digest lactose better to reduce unpleasant symptoms.

Premature babies who are lactose intolerant usually improve once they get older and their digestive tract matures.

Dairy Alternatives

Fortunately, most grocery stores carry dairy alternatives and dairy-free cheese, butter, and yogurt. Non-dairy substitutes for milk include:

• Almond milk
• Soy milk
• Rice milk
• Coconut milk
• Cashew milk
• Oat milk

When to See a Healthcare Provider

If you believe you have a yogurt allergy or any food intolerance, it’s important to speak with your healthcare provider for an accurate diagnosis.

Your healthcare provider may perform a skin prick test or a blood test to check for true milk allergy. They may also order an oral food challenge. Because this could lead to a severe reaction, an oral food challenge must be done in an allergist’s office with emergency equipment on hand.

Summary

A yogurt allergy is usually caused by a milk allergy. The best treatment for a milk or yogurt allergy is to avoid milk and products that contain milk proteins. If you are experiencing gas, bloating, or abdominal discomfort after eating yogurt, you may have lactose intolerance. In order to receive proper treatment, it’s important to visit your healthcare provider for an accurate diagnosis.

A Word From Verywell

Feeling unwell after eating yogurt or other foods you enjoy can be frustrating. Fortunately, there are tests that your healthcare provider can run to help you receive proper treatment. The good news is most grocery stores offer dairy alternatives that will allow you to maintain a milk-free diet while still enjoying your favorite foods.