[Immunologic investigations in children suffering from recurrent respiratory tract infections].

Recurrent respiratory tract infections are a common motif of paediatric consultations. Most of the time, children are healthy and their immune system has a delayed but normal maturation. Sometimes, paediatricians have to rule out an underlying pathology, especially a primary immunodeficiency when a child presents a higher susceptibility to infections. Oriented by the medical history and the physical examination, some laboratory tests will have to be performed. However, their interpretation can be uneasy because it depends on the age, the vaccine status and the infectious medical history. A precise diagnosis should be made in order to rule out a severe primary immunodeficiency. These children may also need a specialized medical environment.