Five patients with a ''blue or purple'' toe syndrome due to atheromato
us embolization probably precipitated by oral anticoagulant therapy ar
e reported. In four, the symptoms started a few weeks after initiation
of oral anticoagulants and in the fifth they were clearly aggravated
by coumarinic drugs. Prior to anticoagulation, one patient had receive
d a course of thrombolytic therapy and two had undergone an arterial c
atherization without embolic events. A diagnostic arteriography perfor
med in four patients caused no new symptoms. All patients had advanced
atherosclerosis. A shaggy aorta and/or pelvic arteries were found in
four and in the fifth a highly stenotic femoral lesion appeared the so
urce of peripheral embolization. Oral anticoagulants were interrupted
in all five and four underwent reconstructive vascular surgery to erad
icate the nidus of atheromatous emboli. One died postoperatively from
multiple organ failure. The poor condition of the fifth patient preclu
ded aorto-iliac surgery. No new episodes of embolization occurred and
the symptoms disappeared, although one patient needed a toe amputation
for a skin lesion that had proceeded to gangrene. The possible role o
f anticoagulant drugs in precipitating atheromatous embolization is di
scussed and the importance of recognizing the syndrome is emphasized.