Familial Mediterranean fever (FMF) is a disease characterized by sporadic, serosal inflammation and unpredictable attacks of fever. This condition is thought to be hereditary and autosomal recessive. Patients often consult with fever, joint pain and intermittent abdominal pain, which progresses as an attack that does not last more than 3 days.1 We discuss a case, rarely reported in the literature, in which the presenting symptom was continuous abdominal pain. An extensive study led to a diagnosis of FMF.

A 49-year-old man of Turkish origin came to our outpatient clinic with isolated, persistent abdominal pain. He had a 10-year history of abdominal pain in the form of continuous shooting pain in left upper quadrant. The attacks of abdominal pain were not very severe, but would last all day and, over the past 5 years, he had noted that the severity did not change upon eating or drinking. The patient had undergone examination with all the advanced radiological techniques, including exploratory laparoscopy focusing on possible sources of the abdominal pain, but no diagnosis had been reached.

The patient's vital signs on admission included a body temperature of 36.3°C, pulse rate of 85bpm, blood pressure of 140/90mm Hg and respiratory rate of 13 breaths/min. There were no notable abdominal findings in the physical examination except tenderness on deep palpation in the left upper quadrant. Tests performed to determine the etiology included complete blood count, routine biochemistry, markers of hepatitis, urinalysis, stool microscopy and culture, thyroid function tests, anti-extractable nuclear antigen antibody profile, culture for Salmonella and Brucella, and tumor markers, and the results were normal or negative. Erythrocyte sedimentation rate was 25mm/h (normal range, 0–20) and C-reactive protein level was 9mg/L (0.2–5). In radiological examinations using advanced techniques, the findings in abdominal ultrasonography and computed tomography, esophagogastroscopy and colonoscopy were normal. Although the patient's clinical presentation was not suggestive of FMF, genetic testing was carried out with this disorder in mind. As a result, a homozygous R202Q mutation was detected. A Tru-cut biopsy taken from the rectum during the colonoscopy revealed AA amyloidosis. The patient was diagnosed with FMF on the basis of abdominal pain, the positive genetic test result and AA amyloidosis. The patient was started on colchicine 3 times daily. After 3 weeks of treatment, the patient's abdominal pain had completely resolved.

In FMF, patients often present with peritonitis, pleurisy, synovitis and skin lesions such as erysipelas. However, approximately 95% of the patients complain of localized abdominal pain. The pain, local at first, progresses to rigidity, adynamic ileus and rebound tenderness, and ultimately spreads to the whole abdomen. The attacks often last up to 3 days.2 Familial Mediterranean fever is caused by a MEFV gene mutation,3 which often occurs in exon 2 or 10. While the prevalent mutation (47–94%) is M694V in exon 10, previous genetic studies have shown that M680, E148Q, V726A, A744S, R202Q, R761H and T267 are also frequent mutations.4 R202Q is a mutation that can be detected quite often in the Turkish population. In studies carried out in Turkey, it has been shown that heterozygous forms produce no symptoms and do not cause amyloidosis, but homozygous forms are associated with the development of symptoms and progression to amyloidosis.

Our patient was admitted to the hospital with a 10-year history of persistent isolated left upper quadrant pain. A homozygous R202Q mutation was detected in the genetic analysis and rectal biopsy revealed AA amyloidosis. The patient responded well to treatment with colchicine.

Thus, FMF should be considered in patients presenting with abdominal pain that is not characteristic of this disorder.