aetiology of cow's milk protein allergy

Last edited 03/2020

Can be IgE mediated or non-IgE mediated:

IgE mediated allergic reaction to milk protein

• IgE-mediated reactions typically occur immediately after ingestion
• IgE-mediated reactions are immediate, requiring only a small quantity of food to be ingested, enabling rapid identification of the allergenic foods - involve the production of specific IgE antibody protein molecules directed against the food protein. It is a well defined mechanism, which is relatively easy to diagnose using a combination of clinical history and validated tests such as skin prick tests and specific IgE’s

Non-IgE mediated allergic reaction to milk protein

• non-IgE mediated are delayed and take up to 72 hours to develop, but still involve the immune system (1) - therefore the identification of suspect foods is often difficult. The mechanism is unclear, it is harder to diagnose and there are no validated tests to confirm such an allergic reaction
• symptoms of non-IgE mediated disease are commonly wrongly labelled as symptoms of intolerance, using either the terms 'lactose intolerance' or 'milk intolerance' (2)

Reference:

• NHS Fife. Diagnosis and Management of Infants with Suspected Cow’s Milk Protein Allergy. A guide for healthcare professionals working in primary care (Accessed 8/3/2020)
• Walsh J et al. Differentiating milk allergy (IgE and non-IgE mediated) from lactose intolerance: understanding the underlying mechanisms and presentations. Br J Gen Pract 2016; DOI: 10.3399/bjgp16X686521