Comparison of results and clinical value of skin prick tests with synthetic and native food allergens in patients at the age of up to 3 years

Skin prick tests are an important diagnostic tool in food allergy, characterized by simplicity and quickness, availability and low cost [1–4]. They can be applied in diagnosis of IgE-dependent reactions [4, 5]. They are considered to be tools particularly useful in exclusion of IgE-dependent reaction to the tested allergens. Thus, positive results do not allow us to introduce a long-term elimination diet but they oblige us to carry out elimination and challenge tests for verification of diagnosis [3].
Currently, there is no minimal limit at which prick tests would be recommended [1, 6] but they are more difficult to perform in small children [2].
Prick tests with standardized synthetic allergens are most frequently performed, less frequent are tests with allergens in a natural form [6–8]. It seems that tests with native allergens can be a useful supplementation of allergological diagnostic evaluation [5, 7].
It has been argued that tests with native allergens can be more sensitive compared to those with synthetic allergens, for example due to the natural content of substances (e.g. enzymes) which are not contained in extracts of standardized allergens or due to the additives added in the process of food production and processing [2, 5]. Thus, in some patients we may observe inconsistent results of tests with synthetic and native allergens, though positive results are believed to be more frequent in the case of natural allergens [5].
We compared the results of prick tests with synthetic and native allergens in order to assess clinical usefulness of both these tests.
The study was conducted in the Department of Pediatrics, Allergology and Gastroenterology of Collegium Medicum of the Nicolaus Copernicus University.
Tests were performed in 53 children aged up to 3 years (mean age: 11.99 ±9.13 months). Children presented with symptoms suggestive of food allergy, including atopic dermatitis, gastrointestinal disturbances, or both.
The analysis involved results of 315 test pairs (tests were performed simultaneously with the same synthetic and native food allergens), including 51 with milk, 38 with egg white, 38 with hen’s egg yolk, and less tests for each of some other allergens; selecting a set of tests in particular patients was based on the data of their medical history (a possible association of symptoms with an intake of a particular food product). We used standardized allergen extracts by Allergopharma and fresh,...


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