Casein is a milk protein present in cow’s milk products and can be problematic if you have casein-milk protein allergy. This condition is often confused with lactose intolerance because they share some symptoms and both are triggered by dairy consumption. However, aside from gastrointestinal discomfort, casein allergy can be life-threatening in severe cases, so it is important to differentiate whether you have true casein allergy or lactose intolerance.
A casein allergy occurs when your body’s immune system mistakenly thinks the protein is harmful and inappropriately produces allergic (IgE) antibodies for protection. The interaction between these antibodies and the specific protein triggers the release of body chemicals such as histamine that cause symptoms which may include:
- Swelling of the lips, mouth, tongue, face, or throat
- Skin reactions such as hives, a rash, or red, itchy skin
- Nasal congestion, sneezing, runny nose, itchy eyes, coughing, or wheezing