Whipple's endocarditis presenting as ulnar artery aneurysm; if you don't look, you won't find

A 54-year-old female patient presented to her local district general hospital with a painful, swollen left arm. Imaging revealed an ulnar artery aneurysm. The aetiology was embolic, with an echocardiogram revealing vegetations on the aortic valve. The patient was treated empirically for 6 weeks with amoxicillin and gentamicin for endocarditis. Eight months later, she had an elective aortic valve replacement for symptomatic aortic regurgitation. The valve was culture negative but analysis by 16S rDNA PCR was positive for Tropheryma whipplei In retrospect, the ulnar artery aneurysm and a history of arthralgia were attributed to an underlying diagnosis of Whipple's endocarditis. She continues on antibiotic treatment with resolution of her arthralgia and no clinical signs of infection. Once thought to be rare entity, molecular assays have revolutionised the diagnosis of Whipple's endocarditis, but this case highlights the difficulties and pitfalls in diagnosis.