Pernicious anemia (patient information)

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Overview
Pernicious anemia is a decrease in red blood cells that occurs when the body cannot properly absorb vitamin B12 from the gastrointestinal tract. Vitamin B12 is necessary for the proper development of red blood cells.

Pernicious anemia is a type of megaloblastic anemia.

What are the symptoms of Pernicious anemia?
People with mild anemia may have no symptoms or very mild symptoms. More typical symptoms of vitamin B12 deficiency anemia include:
 * Diarrhea or constipation
 * Fatigue, lack of energy, or light-headedness when standing up or with exertion
 * Loss of appetite
 * Pale skin
 * Problems concentrating
 * Shortness of breath, mostly during exercise
 * Swollen, red tongue or bleeding gums
 * Nerve damage caused by vitamin B12 deficiency that has been present for a longer time may cause:
 * Confusion or change in mental status (dementia) in severe or advanced cases
 * Depression
 * Loss of balance
 * Numbness and tingling of hands and feet

What causes Pernicious anemia?
When the stomach does not make enough intrinsic factor, the intestine cannot properly absorb vitamin B12.
 * The body needs vitamin B12 to make red blood cells. To provide vitamin B12 to your blood cells, you need to eat enough foods containing vitamin B12, such as meat, poultry, shellfish, eggs, and dairy products. To absorb vitamin B12, your body uses a special protein called intrinsic factor, which is released by cells in the stomach. The combination of vitamin B12 bound to intrinsic factor is absorbed in the last part of the small intestine.


 * Very rarely, infants and children are born without the ability to produce enough intrinsic factor, or the ability to absorb the combination of intrinsic factor and vitamin B12 in the small intestine. Pernicious anemia that occurs at birth (congenital) is inherited. You need the defective gene from each parent to get it.


 * Common causes of pernicious anemia include:
 * Weakened stomach lining (atrophic gastritis)
 * The body's immune system attacking the cells that make intrinsic factor (autoimmunity against gastric parietal cells) or intrinsic factor itself


 * The disease begins slowly and may take decades to fully establish. Although the congenital form occurs in children, pernicious anemia usually does not appear before age 30 in adults. The average age at diagnosis is 60.

Who is at highest risk?
Risk factors include:
 * Family history of the disease
 * History of autoimmune endocrine disorders, including:
 * Addison's disease
 * Chronic thyroiditis
 * Graves disease
 * Hypoparathyroidism
 * Hypopituitarism
 * Myasthenia gravis
 * Secondary amenorrhea
 * Type 1 diabetes
 * Testicular dysfunction
 * Vitiligo
 * Scandinavian or Northern European descent

When to seek urgent medical care?
Call your health care provider if you have symptoms of vitamin B12 deficiency.

Diagnosis

 * Tests that may used to diagnose or monitor pernicious anemia include:
 * Complete blood count (CBC)
 * Reticulocyte count
 * Schilling test
 * Serum LDH
 * Serum methylmalonic acid (MMA) level
 * Serum vitamin B12 level
 * Bone marrow examination (only needed if diagnosis is unclear)
 * Measurement of serum holotranscobalamin II


 * Pernicious anemia may also affect the results of the following tests:
 * Bilirubin
 * Cholesterol test
 * Gastrin
 * Leukocyte alkaline phosphatase
 * Peripheral smear
 * TIBC


 * Vitamin B12 deficiency affects the appearance of cells that form on the outer surface of the body and line inner passageways (epithelial cells). An untreated woman may have a false positive Pap smear.

Treatment options

 * Monthly vitamin B12 injections are prescribed to correct the vitamin B12 deficiency. This therapy treats the anemia and may correct the neurological complications if taken early enough. In people with a severe deficiency, the injections are given more often at first.


 * Some doctors recommend that elderly patients with gastric atrophy take vitamin B12 supplements by mouth in addition to monthly injections.


 * There is also a preparation of vitamin B12 that may be given through the nose. For some people, taking vitamin B12 tablets by mouth in a very high dose can be an effective treatment.


 * A well-balanced diet is essential to provide other elements for healthy blood cell development, such as folic acid, iron, and vitamin C.

Where to find medical care for Pernicious anemia?
Directions to Hospitals Treating Pernicious anemia

Prevention
There is no known way to prevent this condition. However, with early detection and treatment of vitamin B12 deficiency, complications can be minimized.

What to expect (Outlook/Prognosis)?

 * The outcome is usually excellent with treatment.


 * Any damage to nerves may be permanent, especially if treatment is not started within 6 months of when symptoms began.

Possible complications

 * People with pernicious anemia may have gastric polyps, and they are at increased risk for gastric cancer and gastric carcinoid tumors.


 * Brain and nervous system (neurological) problems may continue if treatment is delayed.

Source
http://www.nlm.nih.gov/medlineplus/ency/article/000569.htm