What Is a Janeway Lesion?

A Janeway lesion is a skin abnormality that is associated with different diseases, including infective endocarditis and mycotic aneurysm. The lesions are usually located on the palms and soles, have small diameters, and are non-tender. Typically, no treatment is required for these skin abnormalities, and they often resolve as the underlying disease that caused them to develop is treated.
Diagnosis of a Janeway lesion can generally be made based on its appearance. The lesions tend to be dark red or bright red in color. They can be flat, without being significantly elevated off of the surface of the skin, or can be raised. In other cases, the lesions extend inferiorly into the tissue underlying the skin, and feel firm when touched. They are typically rather small in size, with each lesion having a diameter of a quarter of an inch or less, and often the lesions occur in groups.
Patients typically do not have any pain associated with a Janeway lesion. Most often these skin abnormalities are found on the soles of the feet, the palms of the hands, and the tips of the fingers. Occasionally the skin overlying the lesion can erode, exposing tender underlying tissue, causing pain and inflammation.
The most important reason why diagnosing a Janeway lesion is helpful is that it can herald the presence of an underlying systemic disease. Most commonly, the lesions are associated with infective endocarditis, which is a condition that occurs when bacteria or other pathogens infect the valves of the heart. The Janeway lesion could also indicate the presence of a rarer condition called a mycotic aneurysm, which occurs when a dilation of one of the body’s large blood vessels becomes infected with certain bacterial species.
Finding a Janeway lesion on a patient can help doctors or health professionals diagnose infective endocarditis. In fact, it is one of the minor criteria that can be used to diagnose this condition, according to generally accepted diagnostic criteria for the disease. It is considered to be one of the vascular phenomena associated with the disease, as it occurs due to inflammation of the blood vessels in the body. If five minor criteria associated with infective endocarditis are present, or if three minor criteria and one major criterion is found, then the diagnosis can officially be made.
Most often, patients with a Janeway lesion are not treated for it. This is because the lesions usually resolve on their own as the underlying condition is treated. Patients who experience pain with the lesions could use ointments to soothe the irritation, or could use analgesic medications in order alleviate the pain.