Milk allergy is an immune system reaction to contact with milk proteins resulting in sudden or chronic symptoms which might, in some cases, be life-threatening. It is estimated to affect about 2.5 percent of young children and appears to be on the rise. Before determining if you or your child is allergic to milk, however, it’s necessary to understand the important distinction between an allergy to milk and a milk intolerance, because the symptoms and the treatment of these conditions are quite different.
When you are allergic to milk, the immune system — the part of the body designed to fight infection — mistakenly attacks one or more of the proteins in milk, the most common of which are casein and whey. The symptoms you experience are similar to those seen with other types of allergies and include itching, hives, wheezing and digestive upsets. In severe cases, a condition known as anaphylaxis can occur, in which case breathing and circulatory problems can suddenly occur and result in death. Immediate medical attention is necessary when severe symptoms appear and the administering of epinephrine, also known as adrenaline, through injection is required to reverse any life-threatening risk.
On the other hand, milk intolerance, also known as lactose intolerance, has nothing to do with the immune system. It is caused by the lack of or reduced amount of an enzyme called lactase, which is necessary in digesting milk. Stomach problems such as bloating, cramping and diarrhea are the most common symptoms and, although they can be uncomfortable and annoying, they rarely are life-threatening.
The only way to determine if you are allergic to milk is to consult with an allergist. Skin tests and blood tests normally will be conducted, as will a comprehensive evaluation of your medical history. Through testing, the allergist will look for the presence of immunoglobulin E (IgE) antibodies, which usually are found in the blood and skin of patients who are allergic to milk. The test, however is not infallible, so if you are able to keep a food diary with detailed notes about when you consumed milk and what the reactions were, your physician will be able to make an educated diagnosis despite any variations in testing.
If you are allergic to milk, you must avoid all dairy products and be especially vigilant about coming into contact with milk proteins in any form. Often hidden in common foods and manufactured products, milk proteins can make an appearance as an ingredient in everything from crackers to toothpaste, under the guise of artificial butter flavor, caseinates, lactoglobulin and rennet, among other things. In addition, it is important to note that products labeled "lactose-free," although safe for those with lactose intolerance, are not necessarily safe for someone who is allergic to milk.
Most children who are allergic to milk eventually outgrow their condition. As they get older and that happens, they become able to consume dairy products. Until then, strict avoidance of all milk products is the only sure course of action to take.