Integrated Approaches to Food Allergen and Allergy Risk Management

Integrated Approaches to Food Allergen and Allergy Risk Management

Patients with history of a food allergy to hazelnut, walnut or celeriac will undergo food provocation with a dose of the allergenic food to which 5% of the respective food allergic population (ED05) has been calculated to respond with allergic reactions (single shot study).

In patients with a hazelnut or peanut allergy a double-blind placebo controlled food challenge with cookies containing either placebo or hazelnut and peanut respectively will be performed to determine threshold levels eliciting an allergic reaction. The results for threshold levels determined by cookie matrix will be compared to the results gained from the EuroPrevall project (matrix comparison study).

In patients with a walnut allergy double-blind placebo controlled provocation with walnut will be combined with the intake of proton pump inhibitor (PPI) or with placebo to assess the impact of PPI on the threshold level and on the clinical manifestation.

single shot study, matrix comparison and walnut/PPI study

1. detailed case history, blood sampling and prick testing with different foods will performed.
2. food provocation with a chocolate dessert meal containing either hazelnut, walnut or celeriac (ED05) will be performed (single shot study) in patients with a positive case history of an allergic reaction to either hazelnut, walnut or celeriac or with two meals containing either placebo or hazelnut and peanut respectively in hazelnut and peanut allergic patients or with three meals containing either placebo or walnut in walnut allergic patients.
3. in patients with a negative single shot challenge an open provocation with native hazelnut, walnut, celeriac will be performed unless the patients do not have had a positive previous food provocation with the respective food. In patients with a negative double-blind placebo-controlled food challenge an open provocation with hazelnut or peanut or walnut will be performed to confirm tolerance.

Inclusion Criteria:

• Signed informed consent
• For single shot study: history of a hazelnut, walnut, celeriac allergy due to an unequivocal accidental exposure with typical acute allergic reaction within the preceding 2 years and positive allergen-specific skin prick test/specific Immunoglobulin E or recent positive oral food challenge with hazel, walnut or celeriac within previous 2 years in children <16 years, but no time limit specified for adults
• For matrix comparison study: history of peanut or hazelnut allergy
• For walnut/PPI study: history of walnut allergy. The minimum age for this study is 18 years

Exclusion Criteria:

• Severe disease (heart, liver, kidney), acute febrile infection
• Intake of Ketotifen (past 2 weeks), corticosteroids (past 2 weeks), histamine-1-receptor blocker (past 3 days apart first generation past 7 days)
• Anaphylactic reaction (past 4 weeks)
• Uncontrolled bronchial asthma, forced expiratory volume < 70% predicted
• Pregnancy
• Acute infection or allergy
• Uncontrolled atopic dermatitis
• Chronic urticaria
• Mastocytosis
• Uncontrolled hypertension