Blue Toe Syndrome

Authors:
Pinky Jha, MD, MPH
Medical College of Wisconsin, Milwaukee, Wisconsin

Citation:
Jha P. Blue toe syndrome. Consultant. 2017;57(6):381-382.

A 54-year-old woman with a history of smoking, hypertension, chronic obstructive pulmonary disease, and spinal stenosis presented to the emergency department (ED) with a 7-day history of painful “blue toes.”

History. The patient had sustained a minor injury to her lateral left foot and the fifth digit of her left foot approximately 3 weeks prior. At that time, she had been seen at her primary care provider’s office, where results of radiographs of her left foot were negative for fracture. Approximately 2 weeks later, she reported resolution of her injury but had developed new-onset blue discoloration and pain of the third and fourth toes on her left foot. She had been seen by her podiatrist, who offered no medical intervention and advised her to follow-up in 4 weeks.

Physical examination. Upon presentation to the ED, the patient was noted to have dark blue-purple discoloration of the dorsal and plantar aspects of the third and fourth digits of her left foot, along with diffuse, blanchable, purple-red mottling on the plantar and lateral aspects of her left foot. Bilateral dorsalis pedis pulses were slightly diminished at 2+. No other skin changes were observed. The patient reported having shooting pain accompanied by tingling from her affected toes to just superior to the patella. She denied any systemic symptoms.

Diagnostic tests. A vascular surgery consultant ordered computed tomography angiography (CTA) of the chest, abdomen, and pelvis, the results of which were unremarkable except for atherosclerotic calcifications of the aortic bifurcation and bilateral distal superficial femoral arteries, with greater than 75% narrowing of the lumen of the left popliteal artery. Of note, 3-vessel runoff to the left and right feet was observed. Additionally, transthoracic echocardiography was ordered to rule out cardioembolic causes, and the results were negative.

A diagnosis of blue toe syndrome (BTS) was made.

Treatment. The management plan focused on control of pain, blood pressure, and cholesterol levels. The patient was started on aspirin, 81 mg, and atorvastatin, 40 mg. On the day of discharge, she reported more localized and diminished pain, and mild improvement was noted in the color of the third and fourth toes on her left foot.

Outcome of the case. A few weeks after discharge, the patient had a worsening of left lower-extremity claudication and discoloration of the toes. She was readmitted to our hospital and underwent left lower-extremity angiography followed by left superficial femoral artery stent placement and thrombolysis of left popliteal artery thrombosis. She was started on clopidogrel, 75 mg, upon discharge. The pain and discoloration improved significantly after the procedure.

Discussion. BTS is characterized by the development of blue or purple discolored toes, usually occurring without any report of trauma, cyanosis, or severe hypothermia.¹ BTS is a result of impeded arterial or venous blood flow. BTS usually results from occlusion of vessels by atheromatous particles or atherothrombotic emboli from the aorta or iliac artery. Nevertheless, it is important to rule out other causes such as vasculitis, hypercoagulable state, illicit drug use, and calciphylaxis.¹ A careful history and physical examination are imperative in order to differentiate between the various potential causes of blue toes.

The clinical presentation includes claudication, a bluish discoloration of toes, pain at the site, and skin necrosis. Because the lesions are embolic, they usually start suddenly but may evolve over time. Consequently, early recognition and treatment is important to prevent devastating complications.

Diagnostic procedures should be chosen according to the history, physical examination findings, and patient characteristics. CTA is the preferred choice for imaging of the arteries and the diagnosis of the embolic source (eg, atherosclerotic plaques or aneurysms).

The treatment of BTS depends on the cause. If the cause is atherosclerotic emboli, treatment can be medical or surgical. Medical treatment includes an antiplatelet agent or anticoagulant. Statins are indicated for patients with aortic plaques.² Surgery to remove the source of embolization (eg, aortic endarterectomy) is usually a high-risk procedure. Percutaneous treatment (ie, catheter deployment of stents) is now the standard procedure when a definitive plaque is identified. The need for invasive treatment is dictated by the degree of risk to the patient’s limb.²

Medical management with antiplatelet and anticoagulant therapy followed by delayed percutaneous thrombectomy may be an effective alternative to surgery for treating BTS.

REFERENCES:

1. Hirschmann JV, Raugi GJ. Blue (or purple) toe syndrome. J Am Acad Dermatol. 2009;60(1):1-20.
2. Kronzon I, Tunick PA. Aortic atherosclerotic disease and stroke. Circulation. 2006;114(1):63-75.