A casein test is used to determine if a person is allergic or sensitive to casein, a protein in milk. There are a couple of different ways to test for this allergy. If the test shows that the person is allergic to casein and does not have some other milk sensitivity instead, he or she will need to make some lifestyle modifications. Casein sensitivity or allergy can have a variety of symptoms that range in severity.
There is a casein test that is done at a doctor's office by withdrawing blood and testing it for the antibodies for casein. Several casein tests over a period of time may be needed in order to get an accurate result. A skin casein test may also be done, in which a small amount of casein is inserted into the skin to see if an allergic reaction occurs.
Cutting out milk products completely for at least a week can also serve as a casein test, and is a good first step for someone who thinks that a casein sensitivity might be a possibility. People who are looking to cut casein out of their diets to test for a sensitivity or because they have been diagnosed as allergic need to carefully read labels on foods to check for milk ingredients and the word casein anywhere on the ingredients list. Foods that are labeled as vegan do not contain casein, but lactose free foods are not necessarily casein free.
The severity of this allergy varies. Some people have stomach cramps, rash, stuffy nose, itching, and other uncomfortable but non-threatening symptoms. A small number of people are extremely sensitive to the point that they may go into anaphylactic shock that could lead to death if milk is consumed. The degree to which a person will need to avoid contact with casein can also vary, from being able to consume small amounts of it sometimes to such a degree of sensitivity that food processed on the same surface as milk products can cause an allergic reaction.
A number of infants are allergic to milk, including casein allergy, but outgrow it within a few years. It is possible for an allergy to develop at any age, so a casein test can be done whenever the allergy is suspected. Lactose intolerance is the most frequent reason for people to have problems with milk products, and a true casein allergy is rare.