A food allergy is an overreaction of the body's immune system, which acts as a self defense mechanism - where it recognises the foods consumed as invaders and tries to show up as allergic reactions.

Milk is one of the most common food allergens. Symptoms of the allergy can be from mild to severe, sometimes life-threatening too. This allergy is seen when the child is less than a year old and persist later in life too if the milk's antibodies are present in the body. These children have to forego milk for life.

The symptoms that develop within a short period after consuming milk are

Milk allergy is different from lactose intolerance. Unlike in the case of milk allergy, lactose intolerance does not involve the immune system. A person cannot digest the lactase here, which is an enzyme produced by the small intestine. Symptoms of the lactose intolerance are also similar to the milk allergy symptoms.

Diagnosis of the milk allergy:

Detailed family medical history, including if there was any history of allergic reactions in the family members, what was the food consumed and what were the symptoms like when the visit to the doctor was made. A blood test and a skin prick test to track if any immune-globulin antibodies are present in the body. The body's immune system develops these antibodies which trigger the allergic reactions to neutralise the protein.

Test 1: In the skin prick test, a liquid containing milk protein extract is allowed to seep into the skin, through gentle pricks on the skin. If within few minutes, a red swelling appears on the site, this indicates an allergy present.

Test 2: Blood test checks the presence of antibodies in the bloodstream

Test 3: The third type of test is where the doctor makes the patient eat a small portion of milk products or to drink milk to check for the reactions then and there, with emergency medical help available in case needed.

Once the allergy is ascertained, then the doctor decides on the course of treatment. Usually, it is elimination diet which is recommended.

Treatment: It has been found that there are two main proteins in cow's milk. These are the culprits that cause allergic reactions to occur.

Allergy reactions can be due to either of the above proteins or with one of them. As we are aware, milk proteins are found in most of the dairy products as well.

An allergist will advise avoiding food that contains milk and all by-products of milk. He will further suggest to completely eliminating cow's milk protein from the child's diet. It may so happen that even a small amount can trigger an allergic reaction, sometimes life-threatening. The list of food products to avoid can be as follows:

For people with lactose intolerance, total elimination of cow's milk protein is advised for some time. Some dairy products can be later brought back to the diet, checking for any adverse reactions and testing. It is hence vital to follow the doctor's advice strictly.