Demystifying cows’ milk protein allergy
Cows’ milk protein allergy (CMPA) affects 2% of infants (1 in 50) across Australia and New Zealand and presents with a broad range of symptoms, making diagnosis and management difficult.1-3
What should healthcare practitioners be looking out for and what are common misconceptions?
Food allergy is an abnormal immune response triggered by normally innocuous food protein antigens. Food allergies are broadly classified into those that are IgE mediated, and those that are non-IgE mediated.1–4 In CMPA, the allergic reaction is associated with the protein found in the cows’ milk.5
IgE-mediated allergy is usually rapid in onset (occurring within minutes and up to 2 hours following exposure) and may present as hives and rashes, swelling of the face, abdominal pain and vomiting, breathing difficulties or anaphylaxis. The immune cells involved are IgE antibodies. The nature of an IgE-mediated reaction is unpredictable and can vary in severity and presentation within an individual.1–4
Non-IgE-mediated allergy includes proctocolitis, enteropathy, FPIES and eosinophilic oesophagitis, and primarily affects the gastrointestinal tract. Non-IgE-mediated reactions are generally T cell-mediated, delayed in onset (appearing after 2 hours or days following exposure), dose dependent and are commonly misdiagnosed as lactose intolerance or milk intolerance due to overlapping gastrointestinal symptoms, such as vomiting, diarrhoea, constipation or irritability.1,3,4 CMPA diagnosis should be considered in infants and children when presenting with two or more of the symptoms listed below (full list can be found at allergy.org.au).6,7
Addressing 5 common misconceptions of CMPA
#1 To diagnose CMPA, do infants or children need to present with faltering growth?
Many infants or children with CMPA present with faltering growth, but not all.8,9 The possibility of a CMPA diagnosis should not be dismissed if an infant or child appears to be thriving and growing well.
#2 Are most symptoms caused by cows’ milk due to lactose intolerance?
Lactose intolerance and CMPA (non-IgE-mediated allergy, in particular) are often difficult to diagnose due to a similar presentation of gastrointestinal symptoms. In the majority of cases, gastrointestinal symptoms caused by cows’ milk are most likely to be due to an allergic reaction to the proteins in the milk (CMPA) rather than lactose intolerance.2 Lactose intolerance does not involve the immune system, so while some symptoms maybe similar, lactose intolerance does not cause dermatological or respiratory reactions.1,3,7
#3 Is CMPA over-reported and not often seen in infancy?
CMPA has a prevalence of 2–7.5% in children under 5 years, usually develops in the first year of life and is one of the most common allergies seen in childhood.1,7,14 In any situation where CMPA is indicated or suspected, a diagnosis needs to be performed and in confirmed cases, the allergen removed from the diet.
#4 Do all instances of CMPA in children resolve as they get older?
Population-based studies indicate that in children with CMPA, allergic reactions decrease in severity in >80% of cases by 3 years of age. So over time, some children may be able to tolerate foods that they previously were allergic to, but not all.6,15 Children with CMPA should be reviewed regularly to establish the reaction severity and prevent unnecessary restriction of food containing cows’ milk protein from their diet.
#5 Can you apply a ‘one diet fits all’ to CMPA management?
CMPA management approach should be based on individual circumstances, such as age and severity of the reaction.1,16 Where CMPA is suspected, referral to a specialist and/or dietitian is recommended to provide ongoing supervision, assessment and review of dietary restrictions and to ensure adequate nutritional intake of the infant (and mother, if necessary).1 Several different types of infant formulas are available to help manage CMPA — such as extensively hydrolysed (eHF), amino acid-based (AAF) and soy protein formulas. The table below provides general guidance when selecting an appropriate formula for CMPA.1,16
Treatment guidelines for diagnosed cows’ milk protein allergy (CMPA)16
*Rice protein-based formula not suitable for children allergic to rice.
**Soy protein-based formular not suitable for children allergic to soy.
Additional considerations when choosing a formula:1,16 .
- Formula’s NOT suitable for CMPA include cow’s milk derived formula/milk, lactose free formula/milk, goat’s milk formula/milk, sheep’s milk formula/milk, camel’s milk, partially hydrolysed formula and A2 formula/milk
- AAF should be reserved for infants with severe CMPA symptoms and should NOT be used first line for the management of mild to moderate CMPA in primary care
- Soy milk is not recommended in infants under six months old
- Alternative milks (rice, oat or nut) for children over one year of age should be checked for their calcium (120mg/100mL) protein and fat content to be a suitable cow’s milk replacement
Understanding the differences between infant formulas can seem complicated. Read our article on Inside the tin: a guide to infant formula for cows’ milk protein allergy to understand the differences between the types of formula and to help guide formula choice for your patients with CMPA.
Download our practical guide to diagnosing CMPA – developed by Dr Jeremy Rajanayagam, Royal Children’s Hospital, Melbourne
Nutricia Global Virtual Conference
Featuring 60 international experts, the conference covered a range of topics including education and insight into innovative approaches to understanding and managing CMPA in infants. Sign up to receive content from the Nutricia Global Conference.Learn more
1. ASCIA. Cow’s Milk (Dairy) Allergy. Available at www.allergy.org.au/patients/food-allergy/cows-milk-dairy-allergy(accessed March 2021).2. Venter C. Cow’s Milk Allergy: myth v reality. Available at www.nutricia.co.uk/hcp/resource-centre/cows-milk-allergy-myth-v-reality.html (accessed April 2021).3. Walsh J et al. Br J Gen Pract 2016;66(649):e609–11.4. Boyce JA et al. J Allergy Clin Immunol 2010;126(6 Suppl):S1–58.5. The Royal Children’s Hospital Melbourne. Allergy and Immunology: Cow’s milk allergy. Available at www.rch.org.au/uploadedFiles/Main/Content/allergy/Cows%20milk%20allergy.pdf (accessed April 2021).6. Host A and Halken S. Allergy 1990;45:587–96.7. Fiocchi A et al. WAO Journal 2010; 57–161.8. Isolauri E et al. J Pediatr 1998;132(6):1004–9.9. Christie L et al. J Am Diet Assoc 2002;102(11):1648–51.10. Venter C. CMA – NICE a practical summary. Available from: www.nutricia.co.uk/content/dam/dam/amn/local/gb/approved/eln/cma-nice-practical-summary-pdf (accessed April 2021).11. Department of Health. Lactose intolerance in babies. Available from: healthywa.wa.gov.au/Articles/J_M/Lactose-intolerance-in-babies (accessed April 2021).12. Wright T, Meyer R. Milk and eggs. In: Skypala I, Venter C (eds). Food Hypersensitivity. Oxford: Wiley-Blackwell, 2009. P.117–35.13. Heyman MB. Pediatrics 2006;118(3):1279-86.14. Heine RG et al. Curr Opin Allergy Clin Immunol 2002;2(3):217–25.15. Venter C et al. Allergy 2008;63(3):354–9.16. ASCIA. Guide for Milk Substitutes in Cow’s Milk Allergy. Available from: www.allergy.org.au/hp/papers/guide-for-milk-substitutes-cows-milk-allergy (accessed April 2021).