Final answer:
Osler nodes are the painful lesions found on fingers and toes, typically associated with certain infections like endocarditis. They are tender and raised. In contrast, Janeway lesions, also related to endocarditis, are non-tender and found on palms and soles.
Step-by-step explanation:
The painful lesions found on the fingers and toes that the question refers to are Osler nodes. These are tender, raised lesions that can occur as a result of certain infections, including endocarditis, which is an infection of the heart's inner lining. Unlike Osler nodes, Janeway lesions are also associated with endocarditis but are non-tender and often found on the palms and soles.
Osler nodes are caused by immune complex deposition and have a characteristic painful sensation. On the other hand, Janeway lesions are caused by septic microemboli and do not cause pain. Thus, when differentiating between the two, the presence of pain is a distinguishing feature, with Osler nodes being the painful option.