Physician awareness and understanding of primary immunodeficiency disorders: a web-based study in Japan.

Primary immunodeficiencies (PIDs)/Inborn errors of immunity (IEI) consist of a complex genetic group of disorders that cause susceptibility to infections, inflammation, immune dysregulation, autoimmunity, and malignancy. One of the key steps to reach an early diagnosis is improving knowledge of PID among the medical community. In this study, a web-based survey was conducted among 355 Japanese physicians, consisting of 121 pediatricians, 116 hematologists, and 118 general internal medicine physicians, to assess their awareness and knowledge about the diagnostic flow of PID. One of the major problems this study identified was the unawareness of optimal IgG trough levels among the physicians, while around half the physicians knew about the symptoms of PID. Results from the hypothetical case study revealed that over 70% of physicians considered PID after obtaining the past medical history of patients and 75.2% of physicians showed interest in gaining more knowledge about PID. The survey findings revealed that proper questioning to understand the exact medical history of patients may lead to basic immunological examination. There is a need to improve knowledge about PID, e.g., the '10 warning signs of PID' and '4 stages of testing for PID', and to motivate physicians to ensure earlier diagnosis of PID.