Pernicious anemia is a type of megaloblastic anemia in which there is a deficiency of vitamin B12 in the body, causing symptoms such as weakness, paleness, tiredness and tingling in the hands and feet.
Pernicious anemia, also known as Addison’s anemia, is mainly caused by the body’s lack of a protein that promotes the absorption of vitamin B12 (cobalamin), so that it is eliminated in the urine.
The diagnosis of pernicious anemia is made through laboratory tests, which check the concentration of vitamin B12 in the urine, for example. Treatment is usually carried out through vitamin B12 and folic acid supplementation, in addition to adopting a healthy diet rich in vitamin B12.
Main symptoms
The main symptoms of pernicious anemia are:
- Weakness;
- Pallor;
- Headache;
- Excessive tiredness;
- Diarrhea;
- Smooth and swollen tongue;
- Feeling of a full stomach;
- Weak and brittle nails;
- Tingling in hands and feet;
- Heart palpitations;
- Dizziness;
- Feeling of shortness of breath;
- Irritability;
- Cold feet and hands;
- Appearance of wounds in the corner of the mouth;
- Irritability and sudden changes in mood;
- Decreased libido.
In the most severe cases of pernicious anemia, the nervous system may be compromised, which can lead to difficulty walking, depression and mental confusion.
Possible causes
Pernicious anemia occurs due to the body’s difficulty in absorbing vitamin B12, which happens due to the lack of intrinsic factor, which is a protein that binds to vitamin B12 so that it is absorbed in the body.
The most likely cause of pernicious anemia is immunological: it is likely that the immune system acts unduly 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 situations such as celiac disease, homocystinuria, cobalt deficiency, child malnutrition, treatment with paraminosalicylic acid and poor nutrition during pregnancy, which can cause the baby to be born with pernicious anemia.
How the diagnosis is made
The diagnosis of pernicious anemia must be made by the doctor initially based on the evaluation of the signs and symptoms presented by the person and eating habits. However, to confirm the diagnosis, blood and imaging tests are usually performed. Therefore, the doctor may recommend carrying out a blood count, to assess the amount of red blood cells and hemoglobin circulating in the blood, in addition to the Schilling test, which assesses the amount of vitamin B12 in the urine.
One of the imaging tests that are usually recommended in the investigation of pernicious anemia is digestive endoscopy, as it helps to check whether there are lesions in the stomach. Understand what endoscopy is like.
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 help diagnose anemia. See which tests confirm anemia.
How the Schilling test for vitamin B12 is done
The Schilling test is the laboratory test normally indicated to confirm the diagnosis and consists of the oral administration of vitamin B12 with a marker and, after 2 hours, an injection with vitamin B12 without a marker. After 24 hours, urine is collected and analyzed in the laboratory.
If the presence of the vitamin in the urine is verified, 3 to 7 days after the first test, intrinsic factor associated with vitamin B12 is administered and, after 24 hours, a new urine collection is performed to check whether vitamin B12 is being eliminated. . If there is none, the test is said to be positive for pernicious anemia, as the body has been supplied with a protein that is not being produced and which solves the problem.
Treatment of pernicious anemia
The treatment of pernicious anemia can be done with injections of vitamin B12 containing 50 – 1000µg or oral tablets containing 1000µg of vitamin according to medical recommendation. Additionally, the use of folic acid may be recommended to prevent neuronal consequences.
Treatment is normally carried out for 1 month, and is usually sufficient to resolve the anemia and, consequently, the symptoms. However, there are cases in which it is necessary to maintain vitamin B12 supplementation for life.
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, with the consumption of red meat, eggs and cheese, for example, being normally recommended. See which foods are rich in vitamin B12.
Bibliography
- MONTEIRO, Mirella D.; FERREIRA, Nívia F.; MARINS, Fernanda R.; ASSIS, Isabela B. Megaloblastic anemia: literature review. Saúde em Foco Magazine. 11 edition; 934 – 963, 2019
Sign up for our newsletter and stay up to date with exclusive news
that can transform your routine!
