Images in Nephrology (Section Editor: G. H. Neild) The long-term dialysis patient with purple-blue toes*

Keywords: angioplasty; cholesterol crystal emboli;dialysis; long-term renal replacement therapy;vascular diseaseThe article depicts the situation of a 57-year-oldCaucasian man, on renal replacement therapy since1979 because of membranous and proliferativeglomerulonephritis, who came to the hospital dialysisward complaining of severe foot pain.His long clinical history included about 17 years ondialysis and 8 years of transplantation (three kidneygrafts, which failed because of various combinationsof acute rejection and chronic allograft disease). Heexperienced a myocardial infarction at the age of 45and angina at the time of the third graft. Three monthsbefore the episode described here, he suffered aworsening of claudicatio intermittens and was treatedby angioplasty, with stenting of the left iliac artery andthe right superficial femoral artery; the results of theintervention were considered highly satisfactory.However, severe diffuse vascular disease was presentat all the levels examined (Figure 1).Despite an initial improvement, he experiencedrecurrence of local pain after a couple of months and,in the last few days, had noticed a bluish discolourationof his feet (Figure 2).The most likely clinical diagnosis is cholesterolcrystal emboli syndrome, superimposed on severediffuse peripheral vascular disease. The differentialdiagnosis of subacute painful vascular lesions, aspresented by our patient, takes into account both theevolution of peripheral vascular disease and vasculitisor vasculitis-like lesions. The vascular echo Doppler,performedtakingintoaccountthehypothesisofclosureof the previously treated vessels, was unchanged andrevealed the presence of diffuse vessel lesions but nocritical stenosis, thus ruling out ‘simple’ large/mediumvessel occlusion.As shown in Figure 2, the patient presented diffuselivedo reticularis and two small necrotic lesions.Livedo is a generic sign, common to several systemicmicrovascular diseases including anti-phospholipidantibodies, calciphylaxis and vasculitis [1]. It is amajor form of cutaneous involvement in cholesterolcrystal emboli syndrome, together with ‘blue toes’,vasculitis-like lesions and necrotic lesions [1–4].Concerning the necrotic lesions, an interesting diag-nostic clue came from the location—while ‘pure’obstructive diseases usually lead to very distal lesions,microembolic lesions often appear in more capricious‘non-terminal’ sites, as seen in the figures [1].