The long-term dialysis patient with purple-blue toes**This paper was written in memory of Gianni d'Angelo, a dear friend and teacher.

Abstract

The article depicts the situation of a 57-year-old Caucasian man, on renal replacement therapy since 1979 because of membranous and proliferative glomerulonephritis, who came to the hospital dialysis ward complaining of severe foot pain. His long clinical history included about 17 years on dialysis and 8 years of transplantation (three kidney grafts, which failed because of various combinations of acute rejection and chronic allograft disease). He experienced a myocardial infarction at the age of 45 and angina at the time of the third graft. Three months before the episode described here, he suffered a worsening of claudicatio intermittens and was treated by angioplasty, with stenting of the left iliac artery and the right superficial femoral artery; the results of the intervention were considered highly satisfactory. However, severe diffuse vascular disease was present at all the levels examined (Figure 1). Despite an initial improvement, he experienced recurrence of local pain after a couple of months and, in the last few days, had noticed a bluish discolouration of his feet (Figure 2). The most likely clinical diagnosis is cholesterol crystal emboli syndrome, superimposed on severe diffuse peripheral vascular disease. The differential diagnosis of subacute painful vascular lesions, as presented by our patient, takes into account both the evolution of peripheral vascular disease and vasculitis or vasculitis-like lesions. The vascular echo Doppler, performed taking into account the hypothesis of closure of the previously treated vessels, was unchanged and revealed the presence of diffuse vessel lesions but no critical stenosis, thus ruling out ‘simple’ large/medium vessel occlusion. As shown in Figure 2, the patient presented diffuse livedo reticularis and two small necrotic lesions. Livedo is a generic sign, common to several systemic microvascular diseases including anti-phospholipid antibodies, calciphylaxis and vasculitis [1]. It is a major form of cutaneous involvement in cholesterol crystal emboli syndrome, together with ‘blue toes’, vasculitis-like lesions and necrotic lesions [1–4]. Concerning the necrotic lesions, an interesting diagnostic 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].