What Is an Osler's Node?

An Osler’s node is a skin lesion that can be found in association with a number of different systemic illnesses. These lesions are raised, painful growths most often found on the tips of the fingers or on the soles of the feet. Although they are most commonly associated with a condition called infective endocarditis, in some cases they can develop secondary to marantic endocarditis. This skin lesion is important mainly because its presence often leads to the diagnosis of an underlying disease. No specific treatment is required for these lesions, other than to treat their underlying cause.

The appearance of an Osler’s node is fairly distinctive. It is a raised lesion approximately the size of the pea, ranging in color from pink to blue to purple. In contrast to other skin lesions that might look similar, these lesions often cause pain. They tend to occur on the extremities, most often appearing on the tips of the fingers or on the soles of the feet.

Typically, the reason that an Osler’s node appears is because small arteries or veins become blocked by a clump of material that has become dislodged from the heart, and has traveled through the bloodstream until it reaches small vessels that it cannot pass through. After becoming stuck, the bacteria or other pathologic organisms present in this clump of material can grow. Patients develop an Osler’s node because this material becomes stuck in a small vessel.

Most often, having an Osler’s node is caused by infective endocarditis. In this condition, bacteria or other pathogenic organisms infect the valves of the heart. Less often, the skin lesions can be associated with marantic endocarditis, which is a condition in which there is non-infective accumulation of material, including platelets, on the valves of the heart.

One of the most common reasons medical professionals look for an Osler’s node during an examination is to help make a diagnosis of infective endocarditis. The presence of an Osler’s node is one of the criteria associated with the condition. It is considered one of the minor criteria, and if patients have either five minor criteria, or three minor criteria and one major criterion, they are diagnosed with this infectious disease.

No treatment is typically required for an Osler’s node. The importance of finding these skin lesions is that they can point to the diagnosis of a disease. If patients experience significant pain secondary to the lesions, they can use ointments or take oral pain relievers to help alleviate the irritation. The most important strategy in dealing with the lesions is to treat their underlying cause. With time, and with treatment of the causative disease, the lesions will regress.