Osler nodes are an example of which Duke criterion category?

• A. Major criterion
• B. Minor criterion
• C. Not part of criteria
• D. Echocardiography finding

Answer: (B)

Osler nodes fall under the immunologic phenomena category of the Duke criteria. In infective endocarditis, Duke criteria split findings into major and minor. Major criteria are things like positive blood cultures with typical organisms and evidence of endocardial involvement on echocardiography or new valvular regurgitation. Minor criteria include predisposing heart conditions or IV drug use, fever, vascular phenomena, and immunologic phenomena. Osler nodes are painless or painful nodules on the fingers or toes due to immune complex deposition, reflecting an immune response rather than direct heart infection or a positive culture. That immunologic nature places them in the minor criteria. For memory, remember that Janeway lesions are vascular phenomena (nonpainful), also under minor criteria, while major criteria require microbiologic or echocardiographic evidence.