immunology allergic disorders
Approach to the Patient With Suspected Immunodeficiency
Key Points
Consider a primary immunodeficiency if infections are unusually frequent or severe, particularly if they occur in family members, or if patients have thrush, oral ulcers, periodontitis, or certain skin lesions. Do a complete physical examination, including the skin, all mucous membranes, lymph nodes, spleen, and rectum. Begin testing with complete blood count (with manual differential), quantitative immunoglobulin levels, antibody titers, and skin testing for delayed hypersensitivity. Select additional tests based on what type of immune defect is suspected (humoral, cellular, phagocytic cell, or complement). Test the fetus (eg, using fetal blood, chorionic villus sampling, or cultured amniotic cells) if family members are known to have an immunodeficiency disorder. Teach patients how to avoid infections, give indicated vaccines, avoid live-virus vaccines, and prescribe prophylactic antibiotics for patients with certain disorders. Consider ongoing immune globulin replacement for antibody deficiencies and hematopoietic stem cell transplantation for severe immunodeficiencies, particularly T-cell immunodeficiencies. Although gene therapy is still investigational, advances may make this a viable option in the future. 