Basics

Definition: acrocyanosis is characterized by painless, symmetric, bluish discoloration and coolness most commonly affecting hands and feet. The condition is exacerbated by cold exposure; however, some degree of cyanosis is often present continuously. Other areas affected are:

✓ nose

✓ ears

✓ lips

✓ nipples.

Epidemiology: the exact incidence is unknown, but the condition is relatively uncommon

Prevalence: acrocyanosis is more prevalent among younger females. Prevalence is higher in colder climates.

Risk Factors: abnormal cardiopulmonary function may predispose to the peripheral cutaneous changes seen in acrocyanosis.

Genetics: none known.

Pathophysiology: several theories have been postulated to explain the pathophysiology of acrocyanosis, however the true pathophysiology is not known.

✎ Decreased basal flow through the cutaneous microcirculation is the fundamental defect. This may be secondary to defects in the physiology of the arterioles. Specifically, an increase in vasomotor tone in the arterioles may result in dilation of venules and capillaries.

✎ An alternative theory is that a decrease in blood viscosity plays a key role and that this is exacerbated during cold exposure. This can lead to secondary damage to the capillaries.

✎ A third hypothesis is that elevated levels of endothelin-1, or abnormal responses to endothelin-1, are responsible for the altered microcirculatory physiology.

Etiology: the true etiology is unknown.

• The inciting event may take place in the arterioles, venules, or capillaries.
• The process is likely vasospastic in nature, as opposed to a structural defect.
• Alternatively, an alteration in blood viscosity may lead to capillary damage.

General prevention:

• Management of acrocyanosis is primarily protective.
• Patients are counseled to protect the hands and feet from cold and to avoid extreme temperature changes.

Associated Conditions:

• Cold agglutinin disease
• Cryoglobulinemia
• Anticardiolipin antibodies
• Malignancies
• Various medications, such as tricyclic antidepressants
• Low cardiac output state
• Hypoxemia

Diagnosis

History: the typical patient presents with a chief complaint of painless blue or fingers or toes. Besides, patients complain that their fingers and toes are always cold. These symptoms are worse during cold months. Acrocyanosis onset is often in the second or third decade. Symptoms are often longstanding, and gradual improvement is the norm.

Physical Examination:

★ Inspection reveals cyanosis of the hands, feet, and, occasionally the lips, nose, ears, and nipples.

★ Cyanosis fails to resolve with elevation of the hands or feet.

★ Trophic changes or ulcerations are absent.

★ Peripheral pulses are normal.

Lab tests: baseline laboratory tests should include a complete blood count including platelet count, rheumatoid factor, antinuclear antibody test, and erythrocyte sedimentation rate (ESR) to screen for connective tissue diseases.

Serologic tests to evaluate patients for the presence of a hypercoagulable state can be performed. These include anticardiolipin antibodies, prothrombin gene mutation, protein C and protein S levels, and Factor V Leiden, among others.

Noninvasive imaging:

☝ Imaging tests are indicated only to rule out other causes of peripheral skin changes.

☝ Finger and toe plethysmography are reliable tests to evaluate for digital artery obstruction.

☝ Plethysmographic waveforms are normal in patients with acrocyanosis.

☝ Peripheral arterial examination with segmental pressures can be used to evaluate for proximal obstruction.

☝ Arterial duplex ultrasound examinations can be performed to evaluate for obstruction or aneurysm formation as a proximal embolic source.

Invasive imaging:

⇨ Contrast arteriography or magnetic resonance arteriography is rarely indicated in patients with findings consistent with acrocyanosis.

⇨ Arteriography may be indicated in patients with asymmetric findings on exam or abnormal noninvasive imaging tests.

Differential Diagnosis:

» Vasospastic Raynaud's syndrome

» Arteriosclerotic peripheral vascular disease

» Erythromelalgia

» Peripheral cyanosis

» Livedo reticularis

» Connective tissue diseases (scleroderma, lupus)

» Causalgia

» Drug-induced peripheral skin color changes

Medication (Drugs)

Pharmacologic treatment is rarely needed in true acrocyanosis. In the rare instances of severe symptoms, vasodilator therapy with alpha-receptor blockers have shown some promise in symptom relief. Cases have been reported of improvement using bromocriptine and nicotinic acid derivatives. Calcium channel blockers and low-molecular-weight dextran have been tried but are ineffective.

Surgery: There have been reports of patients experiencing improvement in symptoms after thoracic or lumbar sympathectomy. Although potentially effective, this procedure is rarely indicated for a disease process with a benign course, such as that of acrocyanosis.

Follow-Up

Prognosis: most patients experience improvement over time. Progression to ulceration or digital ischemia is nonexistent in the absence of other pathology. Normal activity and employment should be maintained.

Issues for Referral: referral to vascular or dermatologic specialists is indicated if diagnosis is in doubt or if tissue loss is apparent.