Food Challenge With Barley Starch as Active Comparator

Inclusion Criteria: * Age = 1-20 years * Diagnosed or suspected cereal allergy (at least to one of the following cereals wheat, barley or rye) * Response to cereal proteins confirmed within 2 months in an oral food challenge (OFC)\* OR response to cereal proteins confirmed in an OFC more than 2 months ago but clinically verifiable and documented ongoing cereal allergy at the time of inclusion OR diagnosis confirmed in an OFC with wheat performed as part of the study procedures. * Voluntarily signed informed consent (including willingness to refrain from cereal containing foods for 1 week before intervention period and be exposed to cereal proteins in the test for eligibility) Exclusion Criteria: * Complex food allergy which make elimination diet impossible to accomplish * Patients experiencing unstable or exacerbated atopic disease, such as asthma, atopic dermatitis (AD), urticaria, or allergic rhinitis. * Diseases and conditions that might affect safety. Patients should not be challenged if they have chronic medical the event of anaphylaxis/treatment of anaphylaxis. Examples of such conditions include unstable angina pectoris, cardiac disease or dysrhythmias, severe chronic lung disease. * Pregnancy should be ruled out by testing or based on history (e.g, before menarche) as appropriate * Use of oral corticosteroids. Inhaled and topical steroids or anti-inflammatory medications, such as calcineurin inhibitors or leukotriene antagonists and b-agonists, used at the lowest doses possible and on an established schedule by using fixed doses of medication to maintain a low and stable baseline of atopic disease. Latter medication can usually be continued because their use is unlikely to significantly influence challenge outcomes and their withdrawal might result in exacerbations, affecting disease management and challenge interpretation. * Use of antihistamines during the last 4 days before DBPC challenge or period of 5 half-lives of specific agent. * Prolonged high dose steroids, omalizumab, or possibly other new drugs to control atopic disease upon decision of investigator. * Aspirin/nonsteroidal anti-inflammatory drugs, angiotensin converting enzyme inhibitors, alcohol, antacids and β-blockers upon the decision of the investigator * Any chronic condition or its medication that affect immune system