Tests for Cow's Milk Allergy: IgE, Skin Prick and Food Challenge

Common types of tests

• Skin prick test: quick and direct. You need to stop any medicines that could affect the result, as instructed.
• Specific IgE: a blood test. It is not affected by the condition of the skin. Results are given as a number or a grade.
• Component-resolved testing: this tells apart antibodies against different milk protein parts. It can help in some difficult cases.
• Food challenge: done in hospital following a set process. It is an important way to judge clinical allergy. It also carries some risk, so a specialist doctor must carry it out.

Results cannot be read on their own

A positive test means sensitisation is present. It does not mean symptoms will always happen after eating. A negative test cannot fully rule out clinical allergy either. The doctor will judge based on the actual reaction after eating, how soon symptoms appeared, which body systems were involved and how severe they were. In infants and young children, other conditions such as lactose intolerance, gastro-oesophageal reflux and infectious diarrhoea also need to be told apart.

After you get the report

A doctor should explain it and give a plan for what to avoid, nutrition substitutes and follow-up. Family members should not decide on long-term avoidance or trying to introduce the food based on the numbers alone. This matters most for children who have had a severe reaction before.

This article is for general information only and is not medical advice. Please follow your doctor's instructions.