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identifying the symptoms of cow’s milk allergy

Identifying the symptoms of Cow’s Milk Allergy is the 1st part in this 5-part blog series about Cow’s Milk Allergy in Infancy.

Cow’s Milk Allergy (CMA) is an immune reaction to the proteins found in cow’s milk affecting 1 in 20 infants in the UK.  There are two distinct types of cow’s milk allergy: IgE reactions with immediate onset of symptoms and non IgE reactions with delayed onset.  In both types, symptoms range from mild-moderate to severe and persisting with potentially life-threatening reactions such as anaphylaxis. The following table will help you in identifying the symptoms of Cow’s Milk Allergy.

Delayed Onset Symptoms

Non-IgE Cow’s Milk Allergy

2 – 72 hours after milk intake

Immediate Onset Reactions

IgE Cow’s Milk Allergy

Minutes after milk intake

Affecting formula-fed, exclusively breast fed infants or at the onset of mixed feeding/solids Affecting formula-fed infants or at the onset of mixed feeding
Gastrointestinal symptoms may be mild-moderate or severe and persisting
colic, reflux, loose, frequent stools, soft stool constipation, painful wind,  blood or mucous in nappy, food refusal, feeding aversion, poor growth vomiting, diarrhoea, colic
Skin symptoms can be mild-moderate or severe and persisting
itchy, raised red rash, atopic eczema intense itching, erythema (raised red rash), urticaria (flushing, spreading rash), flare up of atopic eczema, angioedema (facial swelling)
Respiratory symptoms are confined to IgE reactions
acute rhinitis (hayfever), conjunctivitis (swelling in and around the eyes) ANAPHYLAXIS

This blog series will focus on non-IgE CMA with delayed onset, which although less severe can be more complex and difficult to diagnose.  This is due to a number of issues: the similarity to other common conditions during infancy such as colic, reflux or loose stools and also the symptoms being mistakenly treated as lactose intolerance. Again this is due to the similarity in gut symptoms such as colic, bloating, discomfort and diarrhoea.  Unlike IgE CMA, there is no diagnostic allergy test for non IgE CMA and because reactions are delayed up to 72 hours after intake, cause and effect is not quite so clear. Lactose intolerance does not involve immune reactions, but results from lack of the digestive enzyme lactase, with malabsorption of the “milk sugar” lactose  causing discomfort and diarrhoea. A lactose free formula (which normally contains cow’ s milk protein) will resolve lactose intolerance but not Cow’s Milk Allergy,

Non IgE Cow’s Milk Allergy in infancy responds extremely well to prompt dietary treatment, with the majority of infants outgrowing their allergy within 6-12 months.  Delays in diagnosis and treatment lead to symptoms becoming severe and persistent, with feeding difficulties and growth faltering more evident.  Identifying the symptoms of Cow’s Milk Allergy early and discussing an allergy focused history with a trained GP or Paediatric Dietitian will assist making a diagnosis and accessing prompt appropriate treatment.

Next Confirming a diagnosis of Cow’s Milk Allergy.

breast feeding



cow's milk allergy in infancy

delayed reactions



feeding difficulties

food aversion

food refusal

formula feeding

growth faltering

lactose intolerance

poor growth


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  1. Harry
    March 7, 2018 @ 3:06 pm

    Really useful insights, thanks Carine!

  2. Carine Henry
    March 7, 2018 @ 3:38 pm

    Thanks Harry, why don’t you sing up to the blog series, which I will publish over the coming 6 weeks

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