Menstruation in adolescents with familial Mediterranean fever: attack trigger or dysmenorrhoea? A prospective cross-sectional study

OBJECTIVES: This study investigated the relationship between menstruation and familial Mediterranean fever (FMF) attacks in adolescents and whether menstrual symptoms indicate true FMF flares or primary dysmenorrhoea (PD) or premenstrual syndrome (PMS). METHODS: This prospective cross-sectional study included 42 adolescents diagnosed with FMF. Patients with comorbidities, secondary dysmenorrhoea or less than 1 year post-menarche were excluded. FMF attacks were classified according to Eurofever/PRINTO criteria, and CRP was measured on the first and 15th days of attacks and menstruation. Participants were grouped based on self-reported attacks, Eurofever/PRINTO classification and CRP levels (>7.67 mg/l vs ≤7.67 mg/l). Premenstrual symptoms were assessed using the Premenstrual Symptoms Screening Tool. RESULTS: Sixteen patients (38%) reported menstruation-triggered FMF attacks. Mood disturbances (81.3% vs 26.9%, P = 0.002) were significantly more frequent in this group. According to Eurofever/PRINTO criteria, 64.2% were classified as clinical FMF attacks and showed higher M694V homozygosity (55.6% vs 20%, P = 0.049). In the high-CRP group, chest pain (36.4% vs 6.5%, P = 0.032) and M694V homozygosity (72.7% vs 32.3%, P = 0.033) were more common. CRP levels during menstruation increased slightly but remained lower than during typical FMF attacks. PD was reported by 88.1% of patients. Approximately two-thirds of patients met PMS or PMDD criteria, without differences in genotype or inflammatory activity among PMS categories. CONCLUSIONS: Our findings raise the possibility that menstruation does not uniformly act as a trigger for FMF attacks and that a subset of symptoms reported during the menstrual period may reflect premenstrual discomfort or PMS/PMDD-like features rather than true FMF attacks.