Improvement of Diagnostic mEthods for ALlergy assessment. Cashew allergy in children as a showcase (IDEAL study).

There is an urgent need for improvement of the diagnostic tools foorfood allergy. Current tests jeopardize proper diagnosis due to poor sensitivity and false-positive and false-negative results. The current Standard is the double blind, placebo controlled food chanllenge test. This test is expensive. time consuming and includes the risk of allergie reactions. In addition this test is time consuming and can therefore only be performed in approx. 10% of patients. This means that in 90% of patients incomplete diagnostics are performed. This group is gets dietary advice, while it is uncertain whether they really need this. Mediator Release Assays (MRA) are promising tests for superior results in comparision to the current diagnostic tests, because of a superior relationship with the in-vivo situation. MRAs will result in a more relevant diagnosis, less burdenful test protocols for patients and a significant reduction of costs of food challenges. The prevalence of allergy to cashew in children is incresing considerably. The prevalence is unknown and to date no studies addressing the best diagnostic tools have been performed. This study will provide knowledge about the severity and prevalence of this type of allergy and it is expected thatthe newtest method will make the food challenge test redundant.
Because the food challenge test is only performed in 10% of regular patients, this test is seen as a study related test in this study and not as being part of regular diagnostics.



Study design:

Therapeutic non-drug intervention study.
Therapeutic, because the patiënt directly benefits forthe improved diagnostic actions. The diagnosis is more solid and
therefore the dietary councelling can be better targetted.

Conventional diagnostics.

Plus for study purposes:

1. Double blind randomized food challenge test;

2. 6 skin prick tests;

3. Blood draw (12 ml) for Mediator Release Assays
Questionnaires.



200 patients.

Duration approx.2 months per patient.



Patient population:

Children 2 to17 (inclusive) years with suspected allergy to cashew nuts.

Written IC of parents (guardian) and -in case child is 12 years of age or above- also of child.

The hypothesis is that an accurate history, conventional markers of sensitization, IgE antibodies in the serum and positive SPT, and more advanced techniques (MRAs and component resolved diagnosis (CRD)) might predict clinical allergy to cashew nuts. Thereby, the aim of this study is to improve diagnostic procedures for food allergies.

Week 8.

1. Double-blind randomized food challenge;

2. Extra skin prick test;

3. Extra blood sample (12 ml);

4. Completion of questionnaires.