False about Osler’s nodes
**Core Concept**
Osler's nodes are painful, indurated skin lesions that occur in patients with endocarditis, particularly those with subacute bacterial endocarditis (SBE). They are a manifestation of the immune response to the infecting organism, leading to inflammation and thrombosis in the small blood vessels of the skin.
**Why the Correct Answer is Right**
Osler's nodes are typically found on the extensor surfaces of the fingers and toes, and are associated with a poor prognosis, including a higher risk of embolic events and cardiac complications. The nodes are thought to result from the deposition of immune complexes and the activation of the complement system, leading to inflammation and tissue damage. The presence of Osler's nodes is often seen as a sign of the body's attempt to fight the infection, but also indicates a more aggressive disease process.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as Osler's nodes are not typically associated with rheumatic fever. While both conditions involve the immune system and can lead to skin manifestations, Osler's nodes are a hallmark of endocarditis.
**Option B:** This option is incorrect as Osler's nodes are not usually seen in patients with viral infections. The pathogenesis of Osler's nodes involves the deposition of immune complexes and the activation of the complement system, which is more characteristic of bacterial infections.
**Option C:** This option is incorrect as Osler's nodes are not typically associated with vasculitis. While both conditions involve inflammation of the blood vessels, Osler's nodes are a specific manifestation of endocarditis, rather than a general sign of vasculitis.
**Clinical Pearl / High-Yield Fact**
Osler's nodes are a classic example of a "temperature-dependent" lesion, meaning that they are often more painful or tender when the skin is warmed. This can be a useful clinical clue in the diagnosis of endocarditis, particularly in patients with a history of heart disease or a recent history of fever.
**Correct Answer:** C.