What are the different types of cow’s milk allergy (CMA) to consider?
If you think that your baby is showing some signs and symptoms of a food allergy, it’s important to speak to your doctor about your concerns. After asking lots of questions about your baby’s behaviour, your doctor may be thinking, 'Is it cow's milk allergy?'
There are generally two types of this food allergy for the doctor to consider, and which one your doctor suspects will affect how he or she goes about testing your baby for it.
IgE-mediated cow’s milk allergy
In an IgE-mediated allergy, symptoms occur within a few hours after consuming anything that contains cow’s milk protein. This is because the immune system reacts to cow’s milk protein by producing a type of antibody called IgE antibodies, which trigger an immediate allergic reaction.
With an IgE-mediated cow’s milk allergy, you may notice symptoms such as:
- Skin reactions (e.g. itchy rash, hives, swelling of the lips, face and around the eyes)
- Colicky abdominal pain
- Nausea and vomiting
- Hay fever-like symptoms (e.g. sneezing, itchy, runny or blocked nose)
- Breathing difficulties
Which foods contain cow’s milk protein?
In very severe cases, an IgE-mediated allergic reaction could lead to anaphylaxis – a potentially life-threatening allergic reaction that comes on quickly, affects the whole body, and requires medical help straight away. Fortunately, this type of allergic reaction is uncommon.
Find out more about these symptoms here.
Non-IgE-mediated cow’s milk allergy
In a non-IgE-mediated allergy, symptoms can appear after many hours or up to a few days after consuming anything containing cow’s milk protein. The allergic reaction comes on more slowly, as IgE antibodies are not involved.
Some symptoms of a non-IgE-mediated allergy can be similar to those of an IgE-mediated allergy. Others might be less obvious and could be mistaken for something other than a food allergy. The symptoms of a non-IgE-mediated reaction could include:
- Skin reactions or eczema
- Loose or frequent stools, or blood and/or mucus in the stools
- Abdominal pain
- A red or sore bottom
- Breathing difficulties or wheezing
- Failure to thrive
Find out more about these symptoms here.
Mixed allergic reaction
Some babies with cow's milk allergy can have mixed allergic reactions, where they have symptoms of both an IgE-mediated and non-IgE-mediated allergy. This means that the symptoms could come on quickly after eating or drinking anything with cow's milk protein and they could also appear after a few days.
What happens if the doctor suspects an IgE-mediated or non-IgE-mediated allergy?
Your doctor will decide which tests to do, depending on whether they think that your baby has an IgE-mediated or non-IgE-mediated cow’s milk allergy, to pinpoint the right diagnosis.
If your baby is suspected of having an IgE-mediated allergy, it’s likely that they will give your baby an allergy test like a skin prick test or blood test. However, these are not always clear and need to be reviewed by an allergy specialist before a diagnosis can be confirmed. If the results are not conclusive, your child may need to undergo a food challenge. This is where small amounts of the food are given to your child and their symptoms are recorded. The amounts are gradually increased to see what amount they can tolerate.
If a non-IgE-mediated allergy is suspected, your doctor may suggest putting your baby on an elimination diet. This involves removing all foods/drinks containing the suspected food for a period of time and then slowly reintroducing the food to see if there is a reaction. If you are breastfeeding, you may be advised to avoid any cow’s milk protein-containing food or drink from your diet for a period of time.
Always do these tests under the supervision of a doctor and always discuss your concerns with him or her. Please don’t use any tests sold on the high street or online as they may not be reliable; also, the advice and information that they give may not be safe or appropriate for your baby.