Following on from Part 1 (The prevalence and presentation of Cows Milk Protein allergy (CMPA) this chapter explores what to do if you suspect that an infant may have a cow’s milk protein allergy, be it IgE or non IgE.

Referrals from general practice can generally range in babies from around 4 weeks old up to and beyond 18 months old depending on referral pathway, and also the knowledge of the referrer. It has been found in NHS data from 2018, that in the UK there was a 5-6 fold increase in prescription of formula for CMPA, however this was not replicated in a rise in the number of infants that have the diagnosis. This data may therefore indicate that prescribed formulas are being given without correct follow up and that referrals are not being completed to dietetic teams for continued support and correct diagnosis.

There are two typical pathways based on NICE guidance with regards to the referral process. This is dependent on whether you suspect an infant has a delayed (non IgE) allergy or an immediate (IgE) allergy.

Suspected IgE allergy

Following an allergy focussed history, if an infant is reported to be showing symptoms within 2 hours of ingestion of cow’s milk protein, be that either via formula feeding or breastfeeding then it should be suspected that the infant has an IgE allergy.
If breastfeeding then mum should be advised to follow a strict milk free diet and if formula feeding an eHF (extensively hydrolysed formula) should be prescribed. A referral should then be completed to your local allergy services for follow up, allergy testing and dietetic support.

Suspected non IgE allergy – formula fed baby

If you suspect an infant has a non IgE allergy following an allergy focussed history being taken, then first line recommendations would be to provide a 2-4 weeks trial of an eHF after which point a milk challenge should be completed to confirm diagnosis. A referral should also be complete to a dietitian and the milk challenge can be conducted under their care. The milk challenge involves returning to a standard infant formula to identify if symptoms return for the infant.

Suspected non IgE allergy – breastfed baby

If you suspect that a breastfed baby has a delayed cows milk protein allergy then advice would again be the elimination of cows milk and its contained products, however this time through the mothers diet. This is again followed for a period of 2-4 weeks to identify if symptom relief is seen. A referral should also be completed to a dietitian at this stage to support nutritional balance for mum and also to help complete diagnosis via the milk challenge.

Clinical judgement should be used throughout the assessment and diagnosis process and in more severe cases or multiple allergy the use of an amino acid formula (AAF) may be required.

The dietitian plays a key role in the CMPA pathway to support diagnosis and management of CMPA, and prevent nutritional deficiency.

It is important that a milk challenge is completed in infants where it is suspected that there is a delayed cows milk protein allergy to inform next steps with regards to weaning and management of allergy.

Part 3 will explore the next steps in the CMPA pathway and look at the Dietitian’s role.