The World Allergy Organization estimates 520 million people with food allergy on the world. The data that support the prevalence fluctuate in relation of the method employed to obtain these, for example, questionnaires, measurements of IgE-specific, oral challenges; the last one is considerate the gold standard. Similar situation occur to allergy to cow´s milk (CMA), the prevalence reported is 1 to 17.5% in preschoolers, 1 to 13.5% in 5 to 16-year-olds, and 1 to 4% in adults. About 40% of infants referred for specialist management of Gastroesophageal Reflux Disease (GERD) have CMA. This situation increases to 56% in severe cases. These allergic reactions are typically not IgE-mediated. The gold standard for GERD is the pH measurement in 24 hrs (specificity 100%), exist other test more accessible, with considerable sensivity (80%) like scintigraphy.
Methods:
The objective was determinate the frequency of GERD in patients with IgE-mediated CMA. We evaluated retrospectively 20 patients with IgE-mediated CMA of a group of 47 patients with food allergy between 6 months to 39 years aged. They had one or more IgE-specific to proteins that are considered major allergens: casein, beta-lactoglobulin (BLG) or alpha-lactalbumin (A-LA). All the patients had study to discard GERD, through by scintigraphy (study with more access in our Institute). Patients with CMA and negative scintigraphy, had pH measurement. We made three groups, each one to represent the positivity of IgE-specific to major allergens and these was associated with the presence or absence of GERD.
Results:
GERD was found in 80% of patient with CMA. 77.8% of patients with IgE to casein had GERD diagnosed by scintigraphy (p<0.008) Likelihood ratio obtained for this relationship was 7; 70% of patients with IgE to A-LA have GERD (p<0.03), the likelihood ratio was 4. No significant difference was found between the presence of IgE to BLG and GERD. Additionally, we found that 40% of patients with food allergy without CMA presented GERD.
Conclusions:
We found high association between IgE-mediated CMA and evidence of GERD on Mexican people, opposed to previous literature.