RT Book, Section A1 Abbott, Jordan K. A1 Hauk, Pia J. A2 Hay Jr., William W. A2 Levin, Myron J. A2 Abzug, Mark J. A2 Bunik, Maya SR Print(0) ID 1172111145 T1 Immunodeficiency T2 Current Diagnosis & Treatment: Pediatrics, 25e YR 2020 FD 2020 PB McGraw-Hill Education PP New York, NY SN 9781260457827 LK accesspediatrics.mhmedical.com/content.aspx?aid=1172111145 RD 2024/04/19 AB Immune deficiencies that present in childhood comprise rare disorders that have been characterized by a combination of clinical patterns, immunologic laboratory tests, and often molecular identification of the mutant gene. Children with Primary Immunodeficiency (PID) commonly present with recurrent and/or severe bacterial infections, failure to thrive, and/or developmental delay as a result of infection. Immunodeficiency should be considered when infections are recurrent, severe, persistent, resistant to standard treatment, or caused by opportunistic organisms. Because delayed diagnosis of PIDs is common, heightened diagnostic suspicion is warranted.