The Diagnosis: Blue Toe Syndrome
The clinical manifestation suggested blue toe syndrome. A variety of causes for blue toe syndrome are known such as embolism, thrombosis, vasoconstrictive disorders, infectious and noninfectious inflammation, extensive venous thrombosis, and abnormal circulating blood.1 Among them, only emboli from atherosclerotic plaques give rise to typical cholesterol clefts on skin biopsy (Figure 1). Such atheroemboli often are an iatrogenic complication, especially those caused by invasive percutaneous procedures or damage to the arterial walls from vascular surgery. However, spontaneous plaque hemorrhage or shearing forces of the circulating blood can disrupt atheromatous plaques and cause embolization of the cholesterol crystals, which was likely to be the case in our patient because no preceding trigger events were noted.
Figure 1. Biopsy revealed thrombotic arterioles with cholesterol clefts (H&E, original magnification ×200).
Other clinical features also are seen in atheroembolism. Approximately half of patients with atheroembolism develop clinical kidney disease.2 Almost all iatrogenic cases have acute or subacute reduction in glomerular filtration rate of at least to 50% level, whereas the spontaneous cases present as stable chronic renal failure.3 Approximately 20% of patients with atheroembolism also have involvement of digestive organs.4,5 Abdominal pain, diarrhea, and gastrointestinal blood loss are common features; bowel infarction and perforation occasionally occur.5 Pancreatitis is another common complication, and serum amylase levels are raised in approximately 50% of patients.6 Atheroemboli may reach the eyes and brain. They occasionally can cause loss of vision,7 as well as transient ischemic attacks, strokes, and gradual deterioration in cerebral function.3 Blood eosinophilia, which occurs in approximately 60% of patients, is an important finding.3,8