Immunological investigations in children with recurrent respiratory infections.

Respiratory tract infections are common diseases in childhood. Most children with recurrent respiratory infections do not have an immunodeficiency. If they do, this is often due to an antibody deficiency. An important point in the investigation of a child with recurrent respiratory infections is to assess whether the child is thriving. If not, an underlying disease should be sought. Immunological investigations are useful if other, more frequent, underlying diseases have been ruled out. Early immunological screening is mandatory if there is a family history of immunodeficiency. In this review, a protocol is described which identifies children with severe antibody deficiency by simple screening tests before recurrent infections have caused irrepairable damage to the lungs. More elaborate tests are used to detect milder antibody deficiencies. These are reserved for those children in whom symptoms persist.