Evaluation of the adult with suspected immunodeficiency.

Several primary immunodeficiencies may have their initial presentation in adulthood. Although recurrent infections are the hallmark of an underlying immunodeficiency, they need not be the presenting manifestation. This review highlights aspects of infections, as well as noninfectious diseases, that should prompt a high index of suspicion for an underlying immune disorder. The office tests that can be obtained for initial screening and their interpretation are detailed.