Casein Antibody Test in Alaska

What this test measures

Cow's milk contains two main protein groups: casein and whey. Casein accounts for roughly four-fifths of milk protein and is the curd that forms when milk is treated with acid or rennet. An IgE-mediated allergy to casein can cause hives, vomiting, wheezing, or more severe reactions shortly after consuming milk or dairy products.

The test measures allergen-specific IgE against casein in a serum sample. It reports whether antibodies are present and may provide a level or reactivity class. Because casein is present in many dairy foods, including cheese, yogurt, and butter, identifying the specific protein helps guide dietary decisions with a clinician.

A positive result indicates sensitization to casein. Not every sensitized person has symptoms, and milk allergy is more common in young children, some of whom outgrow it. A healthcare provider considers the reaction history, timing, and other tests before advising on avoidance or further evaluation.