Inclusion Criteria:  Proven sensitization to at least one food allergen with a diagnosis of at least one allergic disease for at least one year Clinical diagnosis of allergic rhinitis (AR) for at least 1 year with symptoms of the nose, induced after exposure to allergens via IgE-mediated hypersensitivity reactions (symptoms of watery rhinorrhea, nasal obstruction, nasal itching and sneezing). Diagnosis of atopic dermatitis (AD) with AD symptoms lasting for more than 3 months, with or without food allergy  Additional inclusion criteria:  • Significant clinical allergy to indoor and outdoor allergens, an food allergens with positive skin prick test (SPT) and specific IgE levels (>0.35kUA/L)  Exclusion Criteria:  Known inborn or perinatal pulmonary disease; Pulmonary malformation Oxygen therapy after birth with a duration of more than 24 h Ventilator support or mechanical ventilation after birth Diagnosis of cystic fibrosis Primary ciliary dyskinesia Heart failure diagnosed after birth affecting pulmonary circulation Major respiratory diseases such as e.g. interstitial lung disease and other congenital and serious chronic disease Fever of at least 38.5 °C during the last two weeks prior to the planned visit