Takayasu's arteritis following Crohn's disease in a young woman: any evidence for a common pathogenesis?

Takayasu's arteritis and Crohn's disease are chronic inflammatory diseases of uncertain aetiology. They rarely occur together, with only twenty nine cases of co-existent Takayasu's arteritis and Crohn's disease reported in the literature. In 88% of these cases, Takayasu's arteritis was diagnosed simultaneously or following a diagnosis of Crohn's disease. We present a case of a young Caucasian medical student, incidentally found to have bilateral carotid bruits on auscultation by a colleague. Magnetic resonance angiography revealed stenoses of the common carotid arteries with established collaterals, and a diagnosis of Type 1 Takayasu's arteritis was made. An 18(F)-fluorodeoxyglucose positron emission tomography scan revealed no active disease. Nine months later, she presented with a short history of abdominal pain, vomiting and abdominal distension. Barium follow-through and computer tomography revealed a terminal ileal stricture and proximal small bowel dilation. An extended right hemicoloectomy was performed and histopathology supported a diagnosis of Crohn's disease. This case report is presented with a particular focus on the temporal relationship between these two disease processes and explores whether their concurrence is more than just co-incidence.