Cow’s-milk protein (CMP) is the leading cause of food allergy in infants and young children younger than 3 years. Cow's milk protein (chiefly β-lactoglobulin), is one of the most common food allergen in children (perhaps because it is usually the first foreign protein encountered by infants) and the resulting immune mediated allergic disorder is Cow milk protein allergy (CMPA).It is mainly seen in young children and can involve multiple systems e.g. in the skin as atopic eczema or as urticaria; in the mucosa as angioedema; in the respiratory tract as laryngedema or bronchial obstruction, wheezing; systemically as anaphylaxis; and in the digestive tract, of which all parts of can be affected from the mouth (oral allergy syndrome) to the anus (proctitis). Most GI manifestations of CMPA are due to non-IgE mediated immunity. It is one of the important causes of chronic diarrhea with failure to thrive in infancy. The prognosis for CMPA in infancy and young childhood is good. Approximately 50% of affected children develop
tolerance by the age of 1 year, >75%by the age of 3 years, and >90% are tolerant at 6 years of age.
Myth 1: A disease entity seen in western children alone.
Reality : In the west, symptoms suggestive of CMPA are seen in 5–15% of infants and it’s prevalence is 2–5%.There is Indian data showing it as a cause of malabsorption in 13% children below 2 years of age and also it accounts for chronic diarrhea among 30-35% of children in less than 5 yr of age.
Myth 2: Onset of cow milk allergy can occur after 5 yr of age.
Reality: Almost always CMPA is seen in the first few years of life - majority in the 1st year. Debut of CMPA after 12 months of age is extremely rare. In 2 - 6% of children it’s onset is seen in <3 yrs. of age.
Myth 3: Exclusively breast fed infants can’t develop CMPA.
Reality: By definition, CMPA is excluded if there is no exposure to bovine milk (cow’s milk/buffalo’s milk). However, 0.5% of breastfed baby can develop CMPA due to secretion of bovine protein (beta lactoglobulin) through breast milk when the mother is ingesting bovine milk.
Myth 4: GI involvement in CMPA children leads to diarrhoea not constipation
Reality: Clinical symptoms and signs in the digestive tract may be due to inflammation, dysmotility, or a combination of both. Though diarrhoea is the commonest presentation of GI involvement in children, they can present as constipation in a subset of patients. Chronic iron-deficiency anaemia may be the sole manifestation of CMPA in infants and children.
Myth 5: Diagnosis can be made by atopy patch test, Total IgE and intradermal tests.
Reality: There is no agreement on standardization about the preparation and application of antigen for the atopy patch test besides it’s subjective nature. Neither the determination of total IgE nor the ratio of specific IgE to total IgE offers a benefit over specific IgE alone in the diagnostic workup of CMPA. Intradermal testing should not be performed because it carries a risk of systemic allergic reaction in highly sensitized individuals.
Myth 6: Soy protein formula is the treatment of choice for cows milk protein allergy in all age groups.
Reality: Because of presence of concomitant soy allergy in 10% CMPA patients esp. in non IgE associated symptoms, extensively hydrolyzed formula (eHF) should be preferred to that of soy protein. In infants with extremely severe or life-threatening symptoms, an Amino acid formula (AAF) may be considered as the first choice. Soy protein–based formula may be an option in infants older than 6 months who do not accept the bitter taste of an eHF, or in cases in which the higher cost of an eHF is a limiting factor, provided that the tolerance to soy protein has been established.
Myth 7: Milk from other animal sources can be given in a child with CMPA.
Reality: Cross-reactivity is present among milk proteins obtained from cows, goats and sheep. Only the whey fraction in the goat's milk differs from that in the cow's milk. Goat's milk is tolerated by only 40% of children who are allergic to cow's milk.
Myth 8: Lactose intolerance is same as CMPA
Reality: Both are entirely different entities CMPA being immune mediated requiring complete avoidance of milk and milk products for varying duration while Lactose intolerance is non-immune mediated (enzymatic) and is transient.
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