2.2. Sample collection. Clinical criteria for food allergy definition and diagnostic tests
Patients with FA were recruited at Paediatric Allergy Department of the University Hospital of Ioannina, from July 2019 to May 2021 and blood samples were collected following the World Medical Association Declaration of Helsinki. Informed consent was given from parents and the conducted study has been approved by the Ethical and Scientific Committee (protocol No1290), of University Hospital, Ioannina.
Inclusion criteria were the presence of definite IgE-mediated FA, according to the criteria set by the European Academy of Allergy and Clinical Immunology (EAACI)19. Samples from children with chronic diseases and those on long-term treatment with systemic steroids were excluded from the study. Control group consisted of blood samples from healthy children who visited the outpatient Paediatric department for routine check- up. FA cases and controls were matched for gender and age. During study period, 64 subjects with IgE-mediated FA were enrolled and 44 clinically healthy children, as controls.
Based on guidelines provided by EAACI19 IgE-mediated FA was diagnosed when all clinical criteria were fulfilled. A diagnostic open oral food challenge (OFC)20 and SPTs were also performed; subjects under study were not administrated any antihistamines for a period of ten days before participating in OFC.
Specific IgEs to food allergens, including milk, egg, nuts, cereal, and fish were measured with ImmunoCAP (Phadia AB, Uppsala, Sweden) and 0.35 kU/L value was set as the minimum limit. Sensitization was classified as negative, mono-sensitization or poly-sensitization, based on the number of sensitized food allergens.
Demographic and clinical characteristics of all subjects were recorded. A structured questionnaire regarding breastfeeding, parental smoking, family history of atopy (including the presence of allergic rhinitis, asthma, atopic dermatitis, and FA was completed by the parents and data are presented at Table 1.
TABLE 1: Demographic and clinical data of the studied population.