Results of the population study of the prevalence and risk factors of the food intolerance in children of different school age

Abstract

Background. It is well known that allergy is genetically predispose. But gene change takes much time, ages. Some researches have doubts that it occurred during last two decades, but allergic pathology spread increased in several times more and continue to grow. That’s why the cause should be searched in the epigenetic influences (environmental, food, ets.). More than the half of the modern hypothesis concerning allergy spread are associated with food (7 from 13). EAACI data showed that quantity of children with self reported food hypersensitivity and positive provocation test results decrease with age. But specific IgE levels to food showed other pattern: it increases in young school children in two times and decreases in elders. We supposed different pathogenetic mechanisms of food intolerance (FI) in school children of different ages.

The aim of this study was to assess prevalence, risk factors and features of the FI in children of different school age.

Materials and methods. 250 children 6-17 years old were included into the study. All of them were citizens from the industrial region of the Zaporizhia city. 217 respondents returned questionnaire. 137 of them undergone physical examination. Questionnaire was created on the base of the ISAAC survey and included questions on the life style, food, early age. For the assessment of the skin symptoms severity SCORAD scale was used. Transepidermal water lost was estimated with humidity meter (Queentone,France). Skin pH metria was performed with pH-meter (Ezodo,Taiwan). Statistical analysis was made with Microsoft Exel, Statistica 6.0 programs.

Results and discussion. 217 respondents returned questionnaire (86,8%). 129 (59,4%) of them were males, 88 (40,6%) - females. 85 of children (38,6%) – were pupils from the elementary school (age 6-10 y.o.), 82 children (37,7%) – from the 5-8 classes (age 10-14 y.o.), 50 (23,7%) - 10-11 classes (age 15-17 y.o.).

More than ½ of the respondents (54,3%) had skin food allergy (FA) symptoms in the anamnesis and/or at the exam. And only half of them (28,1%) were consulted by doctor and had verified diagnosis. Quantity of the respondents with eruptions in the elementary school exceeded so in the elderly. That corresponds to the modern tendency of the allergy spread during last decades. Except genetically determined factors big importance had: food during pregnancy and in early childhood, vit D and probiotics intake. Controversial effect had environmental factors and other vitamins.

Conclusions. Only 37,7% of children could name cause of the eruptions. More often it were: citruses, chocolate, honey, strawberry, milk, eggs. Citruses and chocolate mostly cause dose-dependent reactions. Quantity of this reactions increases with age. More than ½ of the children with FA in elementary school had family allergic anamnesis. Hereditary had influence only in children of early school age, but in older age quantity of such patients with reported FI was not more than 30%.Epigenetic influences had bigger influence in this age. FA was reported frequently in families where parents were employed in the industrial factory and rarely in ones where mothers during pregnancy and lactation were on the diet. The most frequent phenotype of children with anamnesis and/or symptoms of FI was dry skin. Algorithm of the FA prophylaxis was proposed.

Further perspectives. Deep allergologic examination should be done for further distinguishing FI.