the Value of Serum Esnophilic Cationic Protein as a Diagnostic Parameter in Infants With Cow Milk Protein Allergy

Cow's milk protein allergy (CMPA) is the most common cause of food allergies in children with incidence estimated as 2% to 7.5% in the first year of life and is characterized by an inflammatory reaction to milk proteins, Formula and exclusively breast-fed babies can develop CMPA.

The immunologic mechanism behind the development of CMPA is not yet clear. However, it is clear that CMPA is caused by IgE- as well as non-IgE-mediated immune reactions, IgE-mediated CMPA is better described and it is typically immediate, type 1 hypersensitivity (minutes to 2 hours after consumption of cow's milk) while non IgE- mediated CMPA is delayed, type 4 hypersensitivity. a diverse range of symptoms of variable intensity in infants.

Combinations of immediate and delayed reactions to the same allergen may occur in the same patient, symptoms and signs related to CMPA may involve many different organ systems, mostly the skin and the gastro- intestinal and respiratory tracts. The involvement of two systems increases the probability of CMPA, whereas some symptoms are more likely to be present in infant with a positive test for CMP-specific IgE (eg, angioedema, atopic eczema); however, there is a large overlap. The same symptoms may appear in CMP IgE-positive and IgE-negative patients, particularly in infant with gastrointestinal manifestations.

Studies in unselected infants with CMPA show that approximately half of them have atopic eczema, and 25% to 50% are affected by some gastrointestinal tract involvement whereas other clinical manifestations are less common.

It is important to accurately diagnose CMPA to avoid the consequences of either under- or overdiagnosis, skin prick test and serum specific IgE tests are helpful for diagnosis, mainly in IgE-mediated forms . On the other hand, in cases of CMPA with gastrointestinal chronic signs and symptoms, skin prick test and specific IgE tests are usually negative.