The need for comparison of oral food challenge outcomes: the ALlergy Diagnosed by Open oR Double blind food challenge (ALDORADO) trial

It is of major importance to diagnose food allergy accurately. Current guidelines support the use of oral food challenges to do so. The double-blind placebo controlled food challenge (DBPCFC) has been regarded as the “gold standard” for decades. However, DBPCFCs are costly, time- and resource intensive procedures. Structural implementation of less demanding open food challenges will only find support if research demonstrates that their outcome will be comparable to DBPCFC, yet this has been proven difficult to investigate. This non-inferiority study has been set up to address the research question to investigate if open food challenges are comparable to DBPCFC in children suspected of having food allergy for cashew nut, hazelnut or peanut.

We hypothesise that the open food challenge is comparable to the “gold standard” DBPCFC in children suspected of having food allergy for cashew nut, hazelnut or peanut.

Participants will undergo both challenges for the specific potential food allergen. We will always start with the DBPCFC, followed by the open food challenge. Furthermore, the DBPCFC outcome will be kept blinded until the last challenge has been performed. Parents will be instructed not to introduce the food into their child’s diet until the last and final test has been performed. We defined unequivocal criteria to decide whether the OFC can be continued in case of (severe) symptoms. In case of an anaphylactic reaction, no further challenges will be planned. The interval between both challenges will be at least one week and no more than six weeks.

All participants will undergo both DBPCFC and open food challenge. DBPCFC is part of usual clinical practice, the open food challenge will be extra. All challenges will be performed according to the European Academy of Allergy and Clinical Immunology (EAACI) guidelines. Prior to the OFCs, as part of usual clinical practice one blood sample will be collected to investigate whether the child is sensitised for the specific food.