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.
See also: Anemia
Alternative NamesMacrocytic achylic anemia; Congenital pernicious anemia; Juvenile pernicious anemia; Vitamin B12 deficiency (malabsorption)
Causes, incidence, and risk factorsThe 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.
When the stomach does not make enough intrinsic factor, the intestine cannot properly absorb vitamin B12.
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:
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.
Risk factors include:
See also: Anemia - B12 deficiency for other causes of low vitamin B12 levels.
SymptomsPeople with mild anemia may have no symptoms or very mild symptoms. More typical symptoms of vitamin B12 deficiency anemia include:
Tests that may used to diagnose or monitor pernicious anemia include:
Pernicious anemia may also affect the results of the following tests:
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.
TreatmentMonthly 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.
Expectations (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.
ComplicationsPeople 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.
Calling your health care providerCall your health care provider if you have symptoms of vitamin B12 deficiency.
PreventionThere is no known way to prevent this condition. However, with early detection and treatment of vitamin B12 deficiency, complications can be minimized.
ReferencesAntony AC. Megaloblastic anemias. In: Hoffman R, Benz EJ, Shattil SS, et al., eds. Hematology: Basic Principles and Practice. 5th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2008:chap 39.
Pernicious anemia is a decrease in red blood cells that occurs when your intestines cannot properly absorb vitamin B12.
See also:
Alternative NamesMacrocytic achylic anemia; Congenital pernicious anemia; Juvenile pernicious anemia; Vitamin B12 deficiency (malabsorption)
Causes, incidence, and risk factorsPernicious ameia is a type of vitamin B12 anemia. The body needs vitamin B12 to make red blood cells. You get this vitamin from eating foods such as meat, poultry, shellfish, eggs, and dairy products.
A special protein, called intrinsic factor, helps your intestines absorb vitamin B12. This protein is released by cells in the stomach. When the stomach does not make enough intrinsic factor, the intestine cannot properly absorb vitamin B12.
Common causes of pernicious anemia include:
Very rarely, pernicious anemia is passed down through families. This is called congenital pernicious anemia. Babies with this type of anemia do not make enough intrinsic factor or cannot properly absorb vitamin 12 in the small intestine.
In adults, symptoms of pernicious anemia are usually not seen until after age 30. The average age of diagnosis is age 60.
You are more likely to get this disease if you:
Certain diseases can also raise your risk. They include:
For information on other causes of low vitamin B12 levels, see: Anemia - B12 deficiency
SymptomsSome people do not have symptoms. Symptoms may be mild.
They can include:
If you have low vitamin B12 levels for a long time, you can have nervous system damage. Symptoms can include:
The doctor or nurse will perform a physical exam. Tests that may be done include:
This list is not all-inclusive.
Pernicious anemia may also affect the results of the following tests:
A woman with low B12 levels may have a false positive Pap smear. That's because a vitamin B12 deficiency affects the cells certain cells, called epithelial cells, look.
TreatmentThe goal of treatment is to increase your vitamin B12 levels.
Your doctor or nurse will also recommend eating a well-balanced diet.
Expectations (prognosis)Patients usually do well with treatment.
It is important to start treatment early. Nerve damage can be permanent if treatment does not start within 6 months of symptoms.
ComplicationsPeople with pernicious anemia may have gastric polyps, and are more likely to develop gastric cancer and gastric carcinoid tumors.
Brain and nervous system problems may continue or be permanent if treatment is delayed.
Calling your health care providerCall your health care provider if you have symptoms of vitamin B12 deficiency.
PreventionThere is no known way to prevent this type of vitamin B12 anemia. However, early detection and treatment can help reduce complications.
ReferencesAntony AC. Megaloblastic anemias. In: Hoffman R, Benz EJ, Shattil SS, et al., eds. Hematology: Basic Principles and Practice. 5th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2008:chap 39.
Antony AC. Megaloblastic anemias. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 167.
Reviewed ByReview Date: 02/08/2012
Todd Gersten, MD, Hematology/Oncology, Palm Beach Cancer Institute, West Palm Beach, FL. Review provided by VeriMed Healthcare Network. Also reviewed by Linda J. Vorvick, MD, Medical Director and Director of Didactic Curriculum, MEDEX Northwest Division of Physician Assistant Studies, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington; David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
Pernicious Anemia
Prognosis is generally good for patients with pernicious anemia
Pernicious anemia seems to run in families
witch vitamin is given to treat pernicious anemia?
An anemia caused by vitamin B12 is pernicious anemia while deficient in iron is iron defeciency anemia.
witch vitamin is given to treat pernicious anemia?
Most patients with pernicious anemia are older, usually over 60
John Frederick Wilkinson has written: 'Hog's stomach in the treatment of pernicious anaemia' -- subject(s): Treatment, Pernicious anemia 'The importance of familial achlorhydria in the aetiology of pernicious anaemia' -- subject(s): Etiology, Achlorhydria, Pernicious anemia 'Treatment of pernicious anaemia with hog's stomach' -- subject(s): Treatment, Pernicious anemia 'Diseases associated with pernicious anaemia' -- subject(s): Pernicious anemia 'Achrestisk anaemi' -- subject(s): Anemia 'L' Anemie achrestique' -- subject(s): Anemia 'The haemopoietic activity of the human liver' -- subject(s): Anemia, Liver, Aplastic anemia 'The value of hog's stomach in treatment' -- subject(s): Treatment, Pernicious anemia 'Achresthic anaemia' -- subject(s): Anemia
Pernicious anemia
Pernicious anemia occurs in equal numbers in both men and women
An increased risk of stomach cancer has been noted in patients with pernicious anemia
generally, pernicious anemia, if autoimmune, is a type 2 hypersensitivity