Milk Allergy

Talk to a healthcare provider if you have symptoms of a milk allergy. They may refer you to an allergist. An allergist is a healthcare provider who specializes in allergies. They can help you diagnose a milk allergy through testing.

Before conducting milk allergy tests, they may ask you questions, including:

• Does anyone else in your biological family have milk or other food allergies?
• Has a healthcare provider ever diagnosed you with food allergies?
• What are your symptoms?
• Do you take over-the-counter (OTC) medications to treat your symptoms?
• When do you notice your symptoms start to appear?
• Do you keep a food journal?

What tests will be done to diagnose a milk allergy?

An allergist may use different allergy tests to help diagnose a milk allergy based on your symptoms. These tests may include:

Blood test

During a blood test, your allergist will use a thin needle (slightly smaller than the size of a standard earring post) to withdraw a small amount of blood from a vein in your arm. The blood sample goes to a laboratory. The lab adds milk proteins to your blood sample and measures the levels of IgE antibodies in it.

It may take a week or longer to get the results from a blood test.

Skin prick (scratch) test

This test exposes your body to small amounts of milk proteins.

Your allergist will first clean a test area of your skin with iodine or alcohol. The test area is usually on your forearm or upper back.

Your allergist will use a thin needle (lancet) to prick your skin with a small amount of liquid containing milk proteins. The lancet won’t go deep into your skin. You’ll only feel a tiny pinch, and you won’t bleed.

Some allergists may use a different method for skin testing. They place a droplet of liquid milk proteins on your skin. They then use a lancet to scratch your skin lightly. The droplets will enter your skin through the scratch. You’ll only feel slight discomfort, and you won’t bleed.

In addition to the milk allergens, the allergist will apply a positive and negative control to your skin. Controls help an allergist compare reactions. A positive control usually contains a histamine solution that causes an itchy, raised response on your skin within a few minutes. A negative control usually contains a saline solution that doesn’t cause a response.

After skin testing, you’ll wait 15 minutes. The allergist will then measure any discolored spots on your skin from the milk test or the controls with a ruler.

A skin prick test takes less than an hour.

Graded oral challenge

To definitively diagnose a milk allergy, your allergist may recommend a graded oral challenge (food challenge). This may be necessary if your history of food allergies and testing don’t match.

You’ll ingest a small amount of milk during a graded oral challenge. Your allergist will then observe you to see if a reaction develops. You may gradually ingest more milk to see how your body reacts.

A graded oral challenge may take up to four hours.