Osler node

Noun

 * 1) A painful, red, raised skin lesion, usually on the pads of the fingers or toes, indicative of the heart disease bacterial endocarditis.
 * The patient had fever and sweats for weeks, but the diagnosis was uncertain until Osler nodes appeared on her fingers.

Usage notes
Modern editors often prefer the non-possessive form of medical eponyms, rather than the older Osler's nodes.