Biological conditions affecting chronic inflammation in upper airways in children

A child's immune system cannot depend on a memory-type immune response and it also induces cytokine responses less efficiently. Biological conditions like allergy or cystic fibrosis, immune deficiency or gastrooesophageal reflux can induce and maintain background inflammation in children's upper airways, making newborns and children more susceptible to upper airway infections and inflammations. This paper will describe in brief how allergy, cystic fibrosis, immune deficiency, nasal and paranasal anatomical variants, and gastro-oesophageal reflux (GOR) can affect the immune and inflammatory responses in upper airways and how they could interfere with immunity development and maturation in children. Literature review. Chronic inflammation induced by infection, allergy, cystic fibrosis or immune deficiency is multifactorial in origin and is strongly influenced by physiological, immunological, anatomical, environmental and, above all, genetic parameters. Finally, the direct role played by nasal and paranasal anatomical variants and GOR is also discussed. These conditions should be screened systematically in all children presenting chronic clinical features of upper airway inflammation.