A casein allergy gets to occur when your body’s immune system thinks that the particular protein intends to tamper your existing sound health conditions. As a result of this, the protective system releases allergic antibodies and when these antibodies interact with the protein substance which in turn results in the release of chemicals such as histamine. At such instances, many symptoms can trigger such as swelling of lips, skin infections, nasal congestion, running nose etc. The Casein Allergy Test is a qualitative allergen IgE blood test that aids to determine whether you’re sensitive to the milk protein or not.