Visakhapatnam: Pernicious anaemia — a decrease in red blood cells due to malabsorption of vitamin B12 — is often confused with Addison’s disease as both present the same clinical features such as gastrointestinal symptoms, hyperpigmentation and hypotension.
A recent study carried out by Dr Srinivas Vaddadi, professor of medicine at the Andhra Medical College, has distinguished between these two medical conditions in a patient through testing of B12 and cortisol levels, which could be a guidepost for future diagnosis of these two conditions.
The intrinsic factor is a special protein produced in the body, helping in the absorption of vitamin B12. But when the body fails to make enough of the intrinsic factor, it leads to malabsorption of vitamin B12. A weakened stomach lining or an autoimmune system attacking the intrinsic factor can be a cause of pernicious anaemia.
Explaining the case of a patient, Dr Vaddadi said, “This 48-year-old diabetic patient’s gastric mucosa was found to be normal during upper gastrointestinal endoscopy. No mass lesions or gastrointestinal tuberculosis were found on CT abdomen. A complete blood picture showed macrocytosis, low B12 levels and positive IgG intrinsic factor antibodies.”
He said the cortisol levels were normal, which was not the case with Addison’s disease, even though it displays the same clinical features of pernicious anaemia.
Hence, the diagnosis of pernicious anaemia (B12 deficiency) was considered. “The patient was given 1,000 µg parenteral B12 daily for two weeks followed by once a week for four months. The hyperpigmentation of hands and feet had resolved with no recurrence in four months,” said Dr. Srinivas.
Dr Srinivas explained another case study of pancytopenia, which was resolved after giving B12 medications after suspecting that the vitamin deficiency could be the root-cause of the disease.
Vitamin B12 deficiency should be considered in all hyperpigmentation cases and early determination of serum B12 levels is vital as it is a treatable condition.
Early diagnosis of B12 deficiency will help in reducing morbidity and hyperpigmentation.
Pernicious anaemia vs addison’s
- Pernicious anaemia is a decrease in red blood cells that occurs when the intestines cannot properly absorb vitamin B12 and the incidence of this condition is about 20 percent all over the world.
- Incidence of B12 deficiency is around 20 per cent all over the world.
- In pernicious anaemia, the gastric parietal cells are targeted by the autoimmune process. Hence, the production of intrinsic factor is affected leading to defective absorption of vitamin B12.
- In Addison’s disease, the adrenal glands do not produce enough steroid hormones. Symptoms which may develop slowly may include abdominal pain, weakness, and weight loss along with darkening of the skin (hyperpigmentation) in certain areas. Under certain conditions, the patient could show low blood pressure, vomiting, lower back pain
