There are two types of intolerance / allergy to Cows Milk Protein (casein).
Cow?s milk allergy (CMA) is often divided into cow?s milk protein allergy (CMPA) where there is clear evidence of involvement of the immune system, and cow?s milk protein intolerance (CMPI) where there is no involvement of the immune system.
Allergies to milk are broadly classified into immunoglobulin E (IgE)-mediated allergy, and non-IgE mediated allergy.
IgE-mediated allergy is commonly referred to as ?immediate hypersensitivity? as the onset of symptoms occurs within minutes to an hour following exposure to the allergen (in this case protein).
Non-IgE-mediated CMA reactions are usually ?delayed? with the onset of symptoms occurring from 1 hour to several days after ingestion of milk; hence it is often called a ?delayed hypersensitivity?.
This excerpt taken from dairy council
My DD is non IgE intolerant of cows milk protein. Avoiding milk is fairly easy in food, less easy in desserts as most are made with butter and cream and milk chocolate. For treats and puddings, best advice is to cook your own using dairy free margarine and dark chocolate.
We use Oatly oat milk, I can cook with it perfectly normally. Vitalite margarine and when baking, I use Stork in the foil wrap. Apart from these substitutes and avoiding chocolate, cheese and yoghurt, ready meals and flavoured crisps, we eat pretty normally.
this website should help