Janeway lesions

Janeway lesions are a peripheral stigmata of infective endocarditis (IE), typically seen in subacute bacterial endocarditis but can occur in acute IE as well. Pathophysiology involves septic emboli breaking off from vegetations on heart valves (commonly caused by Staphylococcus aureus, Streptococcus viridans, or other organisms) and lodging in the microvasculature of the palms and soles, causing microabscess formation with focal necrosis and hemorrhage into the dermis. Histologically, they show microabscesses with neutrophilic infiltration and evidence of septic emboli, without the immune complex vasculitis seen in Osler nodes. Clinically, they present as flat, erythematous, non-tender macules or papules on the palms and soles—key distinguishing feature from Osler nodes, which are tender, raised nodules on the pads of fingers and toes caused by immune complex deposition (type III hypersensitivity). Janeway lesions are part of the Duke criteria (minor criteria) used for diagnosing infective endocarditis, alongside other findings such as fever, vascular phenomena (arterial emboli, septic pulmonary infarcts, mycotic aneurysms, intracranial hemorrhage, conjunctival hemorrhages), immunologic phenomena (Osler nodes, Roth spots, glomerulonephritis, rheumatoid factor), and positive blood cultures not meeting major criteria. Recognizing Janeway lesions clinically should prompt evaluation for endocarditis, including blood cultures and echocardiography (transthoracic or transesophageal). Management focuses on treating the underlying infective endocarditis with appropriate IV antibiotics based on causative organism and sensitivities, with surgical intervention considered in cases of valve destruction, heart failure, or persistent bacteremia.