Triggering factors for febrile attacks in Japanese patients with familial Mediterranean fever.

OBJECTIVES: We occasionally encounter patients with familial Mediterranean fever (FMF) whose attacks are triggered by specific factors; however, information regarding these factors is limited. Our purpose was to identify the factors that trigger febrile attacks in Japanese patients with FMF. METHODS: Our retrospective study included 372 patients (229 women, 143 men) with FMF, who were diagnosed between April 2007 and June 2018. We retrospectively investigated clinical features, genetic variants, and the factors that the patients perceived to have triggered their attacks. Patients completed a questionnaire that included the following triggering factors, anxiety, psychological stress, tiredness, excitement, environmental change, and menstruation. RESULTS: Of 372 patients, 180 (49.4%) reported some triggering factors. Psychological stress and tiredness were commonly reported factors regardless of sex; however, menstruation (39.7%, n=91) was the most commonly reported triggering factor in female patients with FMF. Menstrual-related patients had a younger age of onset and diagnosis, a higher frequency of peritonitis, and a higher rate of patients with endometriosis compared with the non-menstrual-related patients. CONCLUSIONS: Gaining an understanding of these triggering factors could help to reduce attacks and educate the patients. Clinicians may need to consider FMF for patients who have fever and serositis that occurs with every menstrual period.