RESUMEN
OBJECTIVE: To characterize the factors contributing to a greater than 10 year delay in the diagnosis of familial Mediterranean fever (FMF). METHODS: 50 patients, in whom diagnosis of FMF was delayed by more than 10 years, comprised the study population. The clinical, demographic and molecular genetic characteristics were compared to a control group of 50 FMF patients, in whom the diagnosis was made within a reasonable time period (less than 5 years from onset). Additional factors contributing to a delayed diagnosis in the study group, including physician-related factors, patient-related factors, disease-factors and other factors, were studied as well. RESULTS: Overall, attack sites, duration and severity were comparable among study and control groups. No differences in ethnic origin or family history of FMF were noted between the groups. There were significantly more females (p = 0.009), newly-arrived immigrants (p = 0.005) and carriers of unidentified MEFV mutations (p = 0.04) in the study group. Delayed diagnosis of FMF stemmed from misdiagnosis and physician negligence (70%), as well as from patient negligence (70%). The diagnosis was ultimately made mainly due to a change in disease pattern and other causes, such as diagnosis of FMF in a relative. CONCLUSION: The study unveils unexpected causes behind a prolonged delay in the diagnosis of FMF such as social status (immigrant), female gender, physician negligence and lack of patient awareness. The possibility that the delay stems from a milder disease pattern was dismissed.