The Schick test. A useful tool for screening for antibody deficiency

J. L. Sullivan, H. G. Herrod and L. Levine

The evaluation of suspected humoral immunodeficiency includes quantitative immunoglobulin levels and specific antibody assays. The Schick test is a simple procedure for measurement of specific diphtheria antibodies that has been overlooked because the availability of Schick test materials has been limited in recent years. We assessed the efficacy of the Schick test in screening for antibody deficiency states in 23 children. Five had positive Schick test reactions. All five had clinical and immunologic findings consistent with a primary immunodeficiency disorder. Each of these patients had at least one other abnormality of antibody formation detected. The Schick test is a simple screening device helpful in the assessment of immunocompetence.