How do I know my child has a food allergy?

Did you know that there are two different ways the immune system can manifest an allergy?

  • IgE-mediated – this type of response is fairly quick after ingesting the offending food (within 1-2hours), and results in the symptoms most people can recognize as allergy such as wheezing, swelling, rash, vomiting. This is easy to diagnose.
  • Non IgE-mediated – this is a delayed type of allergic response, and can be very subtle and take up to 3 days to manifest. It is difficult to diagnose as tests are often negative, and many of the symptoms overlap with other common childhood conditions like reflux, colic and eczema which can occur WITHOUT allergies.

I’m sure you have all read about the IgE-mediated symptoms and they are fairly easy to recognize. However, I want to talk about the latter which is more challenging.

If your child has one of these conditions, especially in combination, which do not seem to be responding to standard treatment, think about possible food allergies and seek medical advice:

  • Eczema 
  • Reflux or colic
  • Chronic constipation or diarrhea

The problem is that there is no validated test for the Non-IgE type of food allergies, so it is extremely hard to diagnose, even by doctors. A lot of the symptoms that occur (see below list) in this (non-IgE) type of allergy can occur in children without food allergies, which means that often, it is under-diagnosed because doctors label children with colic or reflux without thinking about the possibility of an allergy.

Motherhood brought me to my knees with exhaustion and helplessness and the journey to diagnosis was a painful and prolonged one.

This happened to me with Sarah. And I am an experienced doctor. Hard to admit but before I had Sarah I did not know much about non IgE-mediated allergy. When Sarah started having symptoms of aversive feeding and incessant crying, she was put on maximum dose anti-reflux medication, and I was told she had colic by various doctors, but nothing helped her. Her food refusal was even attributed to some sort of ‘behavioral’ problem, which I had a hard time believing in a 6 week old baby. I saw 4-5 doctors before the correct diagnosis of cow’s milk protein allergy was made. As a mom, I just knew something was wrong with her and I never stopped looking for an answer. I could never put her down – she was always crying, always in pain, and in order to feed her I had to devise some sort of ‘dream-feeding’ technique where she had to be semi-asleep before she would drink any milk. She woke up 5+times at night, usually wailing with pain at the top of her lungs, she cried like that throughout the day too. Motherhood brought me to my knees with exhaustion and helplessness and the journey to diagnosis was a painful and prolonged one.

Consider a food allergy if your baby has a few of the following symptoms in combination:

  • Food aversion/refusal – arching their back when feeding, coming off the bottle/breast during the feed as if in pain, crying during the feed, turning their head away from the bottle
  • Rash
  • Redness of the anus
  • excessive straining (as if opening their bowels) – especially when they seem to strain and then all you see is a small soft, liquid stool in the nappy (straining is usually associated with hard stools. So it would be unusual to strain excessively just to produce a soft liquid stool)
  • Diarrhea or vomiting
  • blood or mucous in their stools
  • Abdominal pain – this is hard to assess in babies but can manifest as distressed crying for no reason and drawing up their legs
  • Writhing around and appearing to strain in their sleep and also uncomfortable stools
  • Faltering growth in conjunction with the above.

It is important you do not use the above list to diagnose your child with an allergy without consulting a doctor as there is a possibility of over-diagnosis due to overlap of symptoms. This list is purely to provide some general pointers; a diagnosis of delayed non-IgE type allergy is very complex and requires a detailed consultation by an experienced allergist. It is also important you do not undertake any elimination diet (i.e. remove certain foods) in you or your child without consulting with a dietician first as this can result in growth impairments with health consequences.

If you have an older child, listen to what they say. Children don’t know how to verbalise their symptoms. e.g. Thomas would tell me the food is ‘sour’ when he is having a reaction. So if they report funny sounding descriptions AND look off-color, they may be reacting to a food. Other common descriptions I’ve heard other children say are:

  • My tongue is scratchy/itchy/sore/hurts
  • There is something in my throat/my throat is itchy
  • There is a bug in my ears/my ears are itchy
  • My belly hurts
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