A 64-year-old man with diabetes and hypertension presented with a 2-day history of sudden onset of acute pain and cyanosis on the sole of his right foot 4 days after undergoing cardiac catheterization and coronary angiography.
A few days later, the patient returned with abdominal pain, diarrhea, and acute renal injury with urinary eosinophils (7% of the white blood cells in the urine) and proteinuria.
Q: Which is the most likely diagnosis?
- Infective endocarditis
- Pernio (chilblain)
- Cholesterol crystal embolism
- Cutaneous small-vessel vasculitis
A: Cholesterol crystal embolism is the correct diagnosis.
Infective endocarditis is an infection of the endocardium, but systemic signs may be present, including cutaneous lesions such as Osler nodes (painful papules on the tips of the fingers and toes) and Janeway lesions (painless macules on the palms and soles). Histologic staining of skin biopsy specimens often shows vasculitis, occasionally with a positive Gram stain. Severe renal injury is not common, and the timing of the acute illness and skin lesion fits better with an acute embolic phenomenon.
Pernio is a form of cold injury, localized in peripheral parts of the body and occurring after exposure to cold temperatures in damp conditions. It usually manifests bilaterally as painful erythematous or purple lesions on the acral areas of the hands and feet, nose, ears, and, rarely, the thighs and buttocks. Pernio most commonly affects women between 20 and 40 years of age. It can be idiopathic or associated with a systemic disease such as systemic lupus erythematosus or Sjögren syndrome.
Cutaneous small-vessel vasculitis is a heterogeneous group of disorders with inflammation and damage of the blood vessels; it may be limited to the skin or it may involve multiple systems. Palpable or nonpalpable purpura and ulceration are common clinical findings, and histologic study shows an inflammatory infiltrate of vessel walls, fibrinoid necrosis, thrombosis, and extravasation of red blood cells.
While this patient’s problems are not consistent with small-vessel vasculitis, the single skin lesion, the timing after the catheterization, and the urinary eosinophils are best explained by cholesterol embolization.
CHOLESTEROL CRYSTAL EMBOLISM
Cholesterol crystal embolism is commonly iatrogenic, a complication of mechanical damage to the arterial walls from vascular surgery or invasive percutaneous procedures. Material dislodged from atheromatous arterial plaques can occlude the small vessels of the feet, producing this syndrome.
The onset of the clinical disease is often delayed for days to weeks after an angiographic procedure.1 Spontaneous hemorrhage, disruption of plaque, or drug therapy with an anticoagulant or a fibrinolytic can precipitate embolization of cholesterol crystals. The source of the emboli is atheromatous plaque in major blood vessels, particularly the abdominal aorta.