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Pernicious anemia, also known as Addison's anemia, is a type of megaloblastic anemia caused by a deficiency of vitamin B12 (or cobalamin) in the body, leading to symptoms such as weakness, pallor, tiredness, and tingling of the hands and feet., for example. Learn more about vitamin B12.
This type of anemia is usually discovered after 30 years of age, however in cases of child malnutrition, for example, there may be a deficiency of this vitamin, characterizing juvenile pernicious anemia.
The diagnosis of pernicious anemia is made mainly through laboratory tests, in which the concentration of vitamin B12 in the urine is verified, for example. Treatment is usually through supplementation of vitamin B12 and folic acid, in addition to adopting a he althy diet rich in vitamin B12.
The symptoms of pernicious anemia are related to the lack of vitamin B12 in the body, the main ones being:
- Smooth tongue;
- Tingling in hands and feet;
- Heart palpitations;
- Shortness of breath;
- Cold feet and hands;
- Appearance of sores in the corner of the mouth.
In the most severe cases of pernicious anemia, the nervous system may be compromised, which can lead to walking difficulties, depression and mental confusion. Learn more about the symptoms of pernicious anemia.
Pernicious anemia is characterized by a lack of vitamin B12 in the body due to impaired absorption of this vitamin due to intrinsic factor deficiency, which is a protein to which vitamin B12 binds to be absorbed by the body. Thus, in intrinsic factor deficiency, vitamin B12 absorption is compromised.
The most likely cause of pernicious anemia is immunological: it is likely that the immune system acts improperly on the gastric mucosa, causing its atrophy and chronic inflammation, which results in increased secretion of hydrochloric acid by the stomach and decreased production of intrinsic factor, thus decreasing the absorption of vitamin B12.
In addition to the immunological cause, pernicious anemia can be caused by conditions such as celiac disease, homocystinuria, cob alt deficiency, childhood malnutrition, treatment with paraminosalicylic acid and malnutrition during pregnancy, which can cause the baby born with pernicious anemia.
How the diagnosis is made
The diagnosis of pernicious anemia is made according to the person's symptoms and eating habits. However, to confirm the diagnosis it is necessary to perform other tests such as digestive endoscopy, which aims to identify lesions in the stomach. Understand how endoscopy is performed.
The laboratory test used to confirm the diagnosis of pernicious anemia is the Schilling test, in which radioactive vitamin B12 is administered orally and 2 hours later an injection containing non-radioactive vitamin B12 is applied. After 24 hours, urine is collected and analyzed in the laboratory. If a low concentration of radioactive vitamin B12 is found in the urine, intrinsic factor associated with vitamin B12 is administered three to seven days after the first test. After 24 hours, the urine is collected and analyzed again and if there is a correction of the concentration of vitamin B12 in the urine, the test is said to be positive for pernicious anemia, since the body was supplied with a protein that is not being produced and that solves the problem.
In addition to the Schilling test, a blood count may be requested, as it is also an exam that allows the diagnosis of anemia. The blood count of pernicious anemia consists of high MCV (Mean Corpuscular Volume) values, since the red blood cells are larger, a decrease in the total number of red blood cells, an increase in RDW, which indicates that there is a great variation between the size of the red blood cells, and the presence of of changes in the shape of red blood cells.
A myelogram may also be requested, which is the test that indicates how the bone marrow is functioning, which in the case of pernicious anemia reveals the presence of large and immature erythroid precursors. This test, however, is invasive and is rarely requested to aid in the diagnosis of anemia. See which tests confirm anemia.
How to treat
Treatment of pernicious anemia can be done with injections of vitamin B12 containing 50 - 1000µg or oral tablet containing 1000µg of vitamin according to medical recommendation.In addition, the use of folic acid may be recommended to prevent neuronal consequences. Learn more about treating pernicious anemia.
It is also important to consult a nutritionist so that you can have better guidance on the foods that should be consumed in pernicious anemia, being normally recommended the consumption of red meat, eggs and cheese, for example. See which foods are rich in vitamin B12.