Osler’s node on the thigh, an uncommon location, but a valuable diagnostic aid

Abstract

A 65-year-old man without any significant past medicalhistory, presented with fever, fatigue and weight loss. Hecomplained of a painful macular violaceous lesion of 2 cm(Fig. 1) located on the left thigh, negative to compression.The remaining physical examination was unremarkableexcept for a slight systolic mitral murmur and conjunctivalhemorrhages.Considering the cutaneous signs although atypical,could be integrated in the Duke minor criteria, we sus-pected a possible endocarditis. Hence, after blood cultures,we started antibiotics using IV amoxicillin (200 mg/kg/day) and gentamycin while scheduling echocardiography.Subsequent laboratory tests confirmed two blood culturespositive for Streptococcus gordonii.Transesophageal echocardiography showed 2 mobilevegetations of 8 and 17 mm on the mitral valve, whichjustified an urgent mitral valve surgery within the next24 h.During the first week after treatment, we observed a fastdisappearance of the cutaneous lesion.The patient recovered after 4 weeks of medical care,followed by removal of a dental granuloma, and is con-sidered healed at 3 years’ follow-up.Is it an Osler’s node or a Janeway lesion? Sir WilliamOsler, in 1893, described the painful sign with his nameassociated ever since. Osler’s nodes are painful and slightlyraised erythematous nodules, from 1 mm to more than1cm[1], commonly located on the pads of the fingers andtoes. Sometimes they are located on the skin of the fore-arms, flank and trunk [2].Then in 1899, Janeway described a different non-tenderlesion found on the palms and soles. The macules, usuallyhemorrhagic, are non-tender, have a variable size, andremain longer than Osler’s nodes [3].Osler’s node on the thigh has never been reportedbefore. Despite some atypical findings, various character-istics of the skin lesion including its size, its shape and itsmarked painful character led us to conclude this was anOsler’s node.Moreover, the histologic findings do not always allowthe physician to distinguish between an Osler’s nodeand a Janeway lesion. Several theories have beenhypothesized for the formation of the cutaneous lesions,and therefore, there is no consensus for specific histo-logic signs. Nowadays septic or bland microemboliseem to explain Osler’s nodes [4] leading sometimes todermal microabscesses with possible isolation of thepathogenic organism from aspirates [5]. However, aphenomenon of an immunologically complex vasculitisis possibility.Osler’s nodes and Janeway lesions might even be theresult of the same process leading to different lesionsaccording to the micro-anatomic site, and the delay inproceeding to biopsy. The virulence of the microorganismresponsible for an acute or subacute infective endocarditismay also play a role in the type of histologicmanifestations.In conclusion, our report suggests that a meticulousphysical examination may allow finding these legendarycutaneous signs that are helpful clues to lead quickly to