PF and FeNO and Clinical Characteristics in Children Being Diagnosed Due to Suspicion of Allergic Diseases

The aim of this study is to assess the influence of kind of allergic disease, allergic profile, allergen exposure, treatment method on lung function parameters, fractional exhaled nitric oxide (FeNO) level in children suspected and being diagnosed due to allergic diseases. Study will be retrospective, conducted in all children diagnosed in the years of 2005-20012 in Laboratory of lung function tests of Department of Pediatrics and Allergy, Medical University of Lodz, N. Copernicus Hospital, Lodz, Poland. The investigators will analyse 5500 male an female children 5-18 year old suspected and being diagnosed due to allergic diseases. In these children nearly 3000 FeNO measurements, 65000 spirometry measurements, 22000 whole-body plethysmography measurements and 48000 occlusion resistance measurements were performed between the years of 2005-2012. The investigators will retrospectively evaluate following data from medical documentation of patients: 1. FeNO levels. 2. Allergic disease diagnosis. 3. Immunoglobulin E (IgE) specific levels. 4. Treatment (drugs and dosages). 5. Lung function parameters (spirometry, whole-body plethysmography, occlusion resistance, bronchial reversibility test).