Casein is a protein found in cow's milk that is responsible for causing milk allergy in some people. Dairy products made with cow's milk and some processed foods also contain casein; making it a difficult allergen to avoid. Children are most likely to suffer from casein allergy; however, adults can also be allergic. Symptoms of a casein allergy can appear minutes to a few hours after ingesting a milk product, according to the MayoClinic.com, and range from mild to severe.
Hives and Swelling
Hives are usually an immediate reaction to a milk allergy. As the body recognizes casein as a foreign substance in an allergic person, it releases large amount of chemicals in the body to get rid of the allergen. These chemicals cause a skin reaction, known as hives, that are raised, red, itchy patches. Hives usually appear on the arms and trunk, but can also develop on the face and neck.
Swelling may accompany hives; lips, eyelids and cheeks can swell and become puffy. These skin reactions are warning signs that a more serious allergic reaction may occur. Anyone experiencing a skin reaction should consider medical treatment to prevent life-threatening allergy symptoms.
Breathing Problems
The same chemicals responsible for causing skin reactions from casein allergy can also cause respiratory reactions. The airway can swell, causing difficulty breathing. Wheezing may result and produce labored, difficult breathing that has a musical or whistling sound with each breath. A person who develops trouble breathing after milk consumption is at risk for further airway problems. The Nemours Foundation website, Kids Health, advises that itchy, watering eyes and sneezing may also develop as a casein allergy symptom.
In some cases, severe allergic reaction, called anaphylaxis, can occur and is life-threatening. An anaphylactic reaction can completely shut-down the airway, causing the victim to stop breathing. Signs of a respiratory emergency are gasping, frequent coughing, labored breathing, audible wheezing or any other indication of breathing distress. These symptoms warrant immediate medical care.
Gastrointestinal Upset
Casein allergy symptoms can also develop as intestinal reactions. Some people may experience nausea, vomiting, heartburn and diarrhea, bloating or flatulence after ingesting casein. Intestinal reactions are also common in people who are intolerant to milk products, but who do not have a true casein or milk allergy. Intolerance to casein occurs when the body rejects casein, but does not release chemicals to attack it. Individuals with a true casein or milk allergy who experience intestinal reaction usually develop additional allergy symptoms as well.
