A case of familial Mediterranean fever presenting with ankylosing spondylitis: A rare case‐report

KEY CLINICAL MESSAGE: The association of familial Mediterranean fever and ankylosing spondylitis is rare, but it is essential to consider this diagnosis in patients with a history of FMF who develop symptoms of back pain or other rheumatologic conditions. ABSTRACT: Familial Mediterranean fever (FMF) is an inherited inflammatory disorder characterized by recurrent fever episodes, abdominal pain, and arthralgia. Ankylosing spondylitis (AS) is a chronic inflammatory disease that affects the spine's joints. The association of FMF and AS is rare. We report the case of a 22‐year‐old male patient with a history of FMF and a positive family history of FMF in his father, who presented with inflammatory back pain. The patient was found to have sacroiliitis on MRI, which is a characteristic feature of AS. The patient was negative for HLA‐B27, a genetic marker often associated with AS. This case report highlights the importance of considering AS in patients with a history of FMF who develop back pain symptoms or other rheumatologic conditions.