Primary Immunodeficiency (PI) disorders are a group of more than 180 inherited disorders, of the approximately 550 inborn errors of immunity (IEIs), that predispose affected patients to a variety of bacterial, viral, and fungal infections. Infections may be more prolonged or severe in patients with PI when compared with immunocompetent patients infected with the same organisms.1,2 Early detection of PI and appropriate short- and long-term management of patients with these conditions have been shown to significantly reduce morbidity and mortality.3,4 However, on average it takes 9-15 years to achieve a diagnosis. Pediatric clinicians should be familiar with the history and clinical characteristics that indicate a potential PI and warrant an initial evaluation and/or a referral to an immunologist for evaluation.
It is estimated that between one in 500 to one in 1,200 people in the United States have a PI, amounting to approximately 250,000 cases.5,6 However, there may be as many as 500,000 undiagnosed additional cases, as evidence suggests that these diagnoses often go unrecognized.7
