A 19-year-old female exchange student presents to the emergency department with severe abdominal pain and a swollen right knee. She has had recurrent episodes of abdominal pain for the past 5 years which last 2-3 days before resolving spontaneously. Previous investigations have all failed to identify a cause. She mentions that several family members back home in Turkey have similar symptoms. On examination, she has a temperature of 39.4°C and a heart rate of 125. Her abdomen is diffusely tender with rebound tenderness. A right knee effusion is present, and a raised, tender erythematous lesion on her left lower leg is noted. Laboratory testing reveals an elevated white cell count with a neutrophilic predominance, as well as elevated ESR, CRP, and SAA protein.
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This patient’s presentation and clinical findings are suggestive of familial Mediterranean fever (FMF), a hereditary autoinflammatory disorder. The disease is characterized by episodic fevers and serosal inflammation that manifests as abdominal and chest pain, and frequently, also joint pain. The diagnosis is typically clinical and supported by the patient’s ethnic background, family history, and genetic testing. When genetic testing fails to uncover a pathogenic MEFV mutation, the diagnosis can be supported by an improvement of symptoms with a trial of colchicine.
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