Evaluating for immunodeficiency in children with recurrent infection.

BACKGROUND: Children have infections more frequently than adults. It may, therefore, be difficult to identify the rare child with immunodeficiency among the many who have recurrent infections but who have a normal immune system. OBJECTIVE: The focus of this article will be on differentiating normal children from those with childhood primary immunodeficiency, through thorough clinical evaluation, and outlining some of the more important immunodeficiency diagnoses. DISCUSSION: When investigating for immunodeficiency, the best available diagnostic tool is a thoughtful clinician with a good working knowledge of what is normal in terms of frequency and severity of childhood infection.