Severe peanut allergy is different from other allergic reactions because it can lead to fatal reactions and is an invisible disability. There is no cure today. The purpose of this study is to treat children and adolescents with severe peanut allergy with oral immunotherapy with peanuts under the protection of anti-IgE (immunoglobulin E) antibodies (omalizumab), and thereby inducing tolerance to peanuts. The treatment will be monitored by basophil cell stimulation (CD-sens).

Oral immunotherapy (OIT), where the food protein is consumed in increasing amounts, have been studied with good results, but allergic reactions has been a major problem. Anti-IgE antibodies (omalizumab) block allergy antibodies so that the allergic reaction is absent. A new test in which basophil cells stimulated with allergen in vitro, CD-sens, showing cell sensitivity, correlates well to peanut challenges.

Twenty children/adolescents, 12 to 22 years, with severe peanut allergy will be treated with omalizumab and the effect evaluated with CD-sens. If the CD-sens is negative a peanut challenge will be performed. If the challenge is negative the OIT will start: 1, 2, 4, 8 g peanuts/day in two-week intervals followed by a maintenance dose of 10 g peanuts/day while continuing treatment with omalizumab. If the CD-sens is still negative the withdrawal of omalizumab will start by halving the dose in several steps.

The study is independent of pharmaceutical companies. Omalizumab is dosed according to body mass and the amount of total IgE antibodies and therefore every individual has an individual study duration. In average the duration of the study is estimated to 52 weeks +/-40/20 weeks. Inclusion in the study is expected to last for the 2 coming years.

A treatment without serious side effects for those with severe food allergies would give a great benefit with reduced anxiety and fear, but also major health economic benefits in the form of fewer hospitalizations, sick leave, and to a greater extent completed school and education.

Inclusion Criteria:

• IgE to peanut, Ara h 1, Ara h 2 and Ara h 3
• IgE to an airborne allergen i.e. cat, dog, horse, birch, grass etc.
• Clinical allergic reactions to peanut the last 5 years
• Positive conjunctival challenge to the selected airborne allergen
• Positive CD-sens to peanut and the selected airborne allergen
• IgE according to the recommendations of the manufacturer
• Written consent

Exclusion Criteria:

• No severe diseases like renal failure, hart disease, immunodeficiency, diabetes or other severe chronic diseases
• Pregnancy
• No previous hypersensitivity reactions to sucrose, histidine, polysorbat 20 or omalizumab