Familial Mediterranean Fever with Psychiatric Disorder which Have not Been Diagnosed over 30 Years: A Case Report.

Familial Mediterranean fever (FMF) is an inherited autoimmune disease characterized by periodic fevers and serositis. Most cases have been diagnosed within 10 years or less; however, there have been no reports of cases in which diagnosis was delayed for several decades. In this study, we encountered a case of FMF in which the patient had recurrent unexplained fevers since childhood, but diagnosis was delayed for more than 30 years due to a psychiatric disorder. Our findings showed that a possible reasons for this delay are possibility of neglect or parenting skills issues, little knowledge of FMF in Japan and the lack of social connections due to the patient's underlying mental illness. We suggest that it is important to conduct a thorough medical interview to identify FMF, as it may go undiagnosed, especially when the patient has few social ties.