The outcomes of oral immunotherapy (OIT) in food allergy study will provide more knowledge of oral immunotherapy. So far the OIT has showed in clinical experiments to be a interesting way to increase the unresponsiveness in severe food allergies. However little is known about it´s long-term outcomes, immunological mechanisms and there are no previous studies about cost-utility of OIT.

The purpose of the present study is to examine the outcomes of the food oral immunotherapy on patients with severe food allergy in the three different subprojects:

Study 1: Long-term follow up after milk oral immunotherapy. The measured outcomes are long-term effectiveness (e.g. health-related quality of life), safety of desensitization and immunological changes.

Study 2: Measure health-related quality of life with disease-specific and generic questionnaire. The aim of this study is to define the suitability of the FAQLQ and the 15-D questionnaires for the Finnish food allergic patients. Another purpose of this study is to examine the relationship between FAQLQ and 15-D questionnaires.

Study 3: QALYs. This is called the cost-utility analyses and QALYs and its purpose is to calculate the cost of OIT and to define the cost-effectiveness of OIT by measuring QALYs. To our knowledge this will be the first pilot study to define the QALYs in food oral immunotherapy. The aim is to have 50-100 patients. The literature in other areas of medicine 50-100 patients in QALY-publishing is quite plain.

Inclusion Criteria:

• Study 1: All the children have been eligible to participate milk OIT during the years 2005-2015.
• Study 2 + 3: Patients will start OIT treatment (to milk / egg / peanut).

Exclusion Criteria:

• Not willing to participate
• Active asthma, low lung function, pregnancy, cardiovascular or other disease that might worsen during the OIT.