Polycythemia Vera

Alternative names: PV

The excessive numbers of red blood cells produced in polycythemia vera increases the volume of blood and makes it thicker so that it flows less easily through small blood vessels.  However, the number of red blood cells may be increased for a long time before symptoms appear.

Incidence

Only five people out of every million have this rare condition.  Men are twice as likely as women to develop the condition.  People older than 60 are most likely to develop the condition, though it may happen at any age.

Signs and Symptoms

The earliest symptoms frequently include

• weakness
• fatigue
• general malaise
• headache
• light-headedness
• shortness of breath
• stomach aches
• vision disturbances (distorted vision, blind spots, or flashes of light)
• gastrointestinal bleeding
• blood in the urine
• bleeding from the gums
• bleeding from small cuts
• red or darkened/purple blotchy spots or patches of skin, especially on the face
• itching all over, particularly after a hot bath
• throbbing and burning sensations in the hands and feet
• (more rarely) bone pain
• liver and spleen enlargement, causing a dull, intermittent ache in the abdomen
• high blood pressure
• blockage of blood vessels leading to potential heart disease, stroke, or gangrene (tissue death) of the arms and legs.

The excess of red blood cells may be associated with other complications, including stomach ulcers, kidney stones or clotting in veins and arteries, which can cause heart attacks or strokes and can block blood flow to the arms and legs.

Diagnosis and Tests

Hemoglobin levels and hematocrit are abnormally high when this condition is present.  A hematocrit reading higher than 54% in a man or 49% in a woman may indicate polycythemia, but the diagnosis can not be made on the basis of this alone.  A test that uses radioactively-labeled red blood cells to determine the total number of red blood cells in the body can help make the diagnosis.  Rarely, a bone marrow biopsy is needed.

Treatment and Prevention

The aim of treatment is to slow down production and decrease the number of red blood cells.  Blood is usually removed from the body in a procedure called a phlebotomy: a pint of blood is removed every other day until the hematocrit begins to decrease.  When the hematocrit reaches a normal level, blood is removed every few months, as needed.

Treatment with medication (myelosuppressive therapy) is also available.

To help control some of the symptoms, antihistamines can help relieve itching, and aspirin can relieve burning sensations in the hands and feet as well as bone pain.

Hydroxyurea (Droxia, Hydrea) or anagrelide (Agrylin) reduces number of blood cells.

Low-dose aspirin reduces skin redness and burning, and lowers increased temperature that may occur.

Allopurinol reduces symptoms of gout, a potential complication of polycythemia vera.

Prognosis; Complications

Without treatment, about half the people who have polycythemia vera with symptoms die in under 2 years.  With treatment, they live for an average of 15 to 20 years.

Rarely, polycythemia vera progresses to leukemia; certain treatments increase this likelihood.