Article Text
Abstract
BACKGROUND Cow`s milk allergy is among the most common food allergy in children. It may be defined as a reproducible adverse reaction of an immunological nature induced by cow`s milk protein.
The undergoing mechanism can be Ig E mediated with immediate onset and non IgE mediated or delayed onset type. The prevalence is between 1,8% and 7,5% of infants during the first year of life.
With evidence of increasing food allergy prevalence and more persistent disease, it has become vital to improve the management of CM allergy. The ability to tolerate backed milk such as in muffins or cake has been associated with an increased chance of tolerance development.
Exposing milk proteins to high temperatures through baking reduces allergenicity by destroying conformational epitopes.
The whey proteins in cow milk, such as alpha-lactalbumin and beta-lactoglobulin, contain conformational epitopes that are heat labile (significantly reduced after 20 min of boiling), whereas casein contains mostly sequential and heat resistant epitopes.
Design From January to December 2016, 91 children between 0–3 years were referred to allergy department of which 35 (38.46%) with suspected IgE-mediated hypersensitivity reaction to cow’s milk protein.The allergy workup by skin prick testing, IgE levels confirmed the diagnose in 21 children (23%). For oral challenge tests were selected only 12 cases, wich have had negative result for casein both in skin prick test and sIgE in order to decrease the immediate risc
Allergy Evaluation
Skin prick test was performed according to previously published methods using single test device (Stallergenes) and commercially prepared extracts (Lopharma,Italy). Control tests for skin prick test were performed with histamine (positive control) and normal saline (negative control).
All the subjects have had the skin prick test and sIgE measured at the time of oral challenge.
Oral challenge
Baked milk challenges were performed as open challenge under physician supervision in outpatient conditions. The muffins were baked in safe conditions as per protocol. Each muffin contained 1,3 grams of milk protein. The muffins were backed at 180°C for 30 min. The oral food challenge started with few crumble under the tongue and afterwards increasing increments every 15 min totaling with 2 muffins at the end of challenge wich corresponds to 2,6 grams of milk protein. Subjects were monitored throughout and 2 hours after challenge.
Results Twelve children (median age 2,95 years, range 1,8–7 years) underwent food challenges to baked milk – muffin. Ten children (83,33%) passed the baked milk challenge and two (16,66%) failed. We have found approximately the same data in the literature. No differences were found between genders. The childrens how have failed the challenge didn`t have preexisting atopic conditions (asthma, rhinoconjunctivitis, eczema).
Skin prick test for alpha lactalbumin (median 0, range 0–10) and sIgE could not be correlated (P = – 0,233), but we found a moderate correlation between skin prick test for betalactoglobulin (median 1,5 range 0–8) and the sIgE for betalactoglobulin (p=0,05).
Oral food challenge failure
Two children, subject 8 and 10 have failed the oral challenge. No child who failed developed anaphylaxis or required epinephrine.
Subject 8–3,8 years passed the initial clinic challenge to muffins (2,6 grams) and she continued consuming at home. In the day 3 after challenge she developed rhinoreea followed by nose congestion and periorbitar angioedema symptoms appeared 10 min after half a muffin. The subject was treated at home with oral antihistamines.
Subject 10–7 years also passed the initial clinic challenge to muffins (2,6 grams). At home he continued to eat 2 muffins/day. The family reported a mild erythematous eruption over the trunk, raising the anxiety of the family so they decided to discontinue the introduction of cow milk protein.
Discussion Cow`s milk allergy is the most common food allergy among children. The ability to tolerate baked milk, such as in cake or muffin, has been associated with an increased chance of tolerance development. Being able to add baked milk into diet can also increase quality of life by expending the diet, boosting nutrition, and promoting inclusion in social activities.
To date, reliable markers for selecting subjects for baked milk challenge have not been clearly established. Therefore oral challenge to baked milk remains the gold standard.
We found 83,33% of milk allergic children have passed the oral food challenge, wereas 16.66% have failed.
We found no correlation between the skin prick test and sIgE for alfa-lactalbumina and moderate correlation between the skin prick test and sIgE for betalactoglobulin.
The two subjects how have had reacted at home we can presume that they were exposed unintentionally to undercooked products.
In summary extensively heated milk (baked) are tolerated by most of the children with IgE mediated allergy to unheated milk. Current evidence favours incorporating baked milk into the diet of children who can tolerate them because it appears to be safe, to be well tolerated, and to accelerate development of tolerance to unheated milk.
- cow milk allergy
- baked milk
- extensively heated milk
- muffin test