Is familial Mediterranean fever (FMF) common in patients with negative appendectomy?

Abstract Objectives Familial Mediterranean fever (FMF) is an autosomal-recessive disease characterized by recurrent attacks of fever with serositis. Differential diagnosis of a FMF abdominal attack with acute abdomen is difficult. Acute appendicitis is the most common cause of acute abdominal pain that requires surgical treatment. The aim of this study was to investigate frequency of FMF in patients with negative appendectomy. Methods We assessed 278 patients (female/male 127/151) who were operated with preoperative diagnosis of acute appendicitis. In 250 of the patients, definitive diagnosis of acute appendicitis was established by histo-pathological examination. Patients with negative appendectomy were assessed for FMF by rheumatologist. Results Negative appendectomy was detected in 28 patients (M/F 5/23, mean age 25.3 ± 8.4 years). Negative appendectomy ratio was 10.1 %. Among 28 patients two had FMF (7.7 %). Conclusions FMF were established in 7.7 % of patients with negative appendectomy. Our study suggests patients having negative appendectomy should be evaluated for FMF. Further large sample studies are needed to define the real prevalence of FMF among negative appendectomy patients.