Which of the following is not a cause for pernicious anaemia?

KPSC Staff Nurse - 2018

Medical Surgical Nursing

Hard

Appeared in: KPSC Staff Nurse - 2018

Explanation

The question asks to identify the option that is not a cause of pernicious anemia.
Bleeding, especially chronic bleeding, leads to the loss of iron from the body.
This results in iron-deficiency anemia, which is a microcytic anemia (small red blood cells), not the macrocytic anemia characteristic of pernicious anemia.
Pernicious anemia is a specific type of vitamin B12 deficiency anemia and is unrelated to iron levels or blood loss as a primary cause.

Option B: Chronic alcoholism can lead to nutritional deficiencies, including both folate and vitamin B12, due to poor intake and malabsorption. While it causes a macrocytic anemia similar to pernicious anemia, it is not the specific autoimmune cause of pernicious anemia itself, but it is a recognized cause of general B12 deficiency.
Option C: Long-term use of certain drugs, such as proton pump inhibitors (PPIs) and metformin, can interfere with the absorption of vitamin B12. This can lead to a B12 deficiency and macrocytic anemia. Like alcoholism, this is a cause of B12 deficiency, but not the specific autoimmune condition of pernicious anemia.
Option D: This is the defining cause of pernicious anemia. Pernicious anemia is an autoimmune condition where the body attacks the parietal cells of the stomach, leading to a lack of intrinsic factor (IF). Without IF, vitamin B12 cannot be absorbed in the terminal ileum. Since this is the primary cause, it cannot be the answer to a question asking what is not a cause.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Etiology of Pernicious Anemia as background academic context rather than a clinical decision trigger.
A key nursing responsibility is to differentiate symptoms. While all anemias cause fatigue and pallor, only B12 deficiency causes neurological symptoms like paresthesia (tingling) and ataxia (gait problems). A nurse's neurological assessment is crucial.
Patient education is vital. Patients with true pernicious anemia require lifelong intramuscular B12 injections because oral B12 cannot be absorbed without intrinsic factor.
What if? If a patient with known pernicious anemia reports new-onset dark, tarry stools (melena), the nurse must act immediately. While the melena indicates bleeding (which would cause iron-deficiency anemia), it doesn't change the underlying diagnosis of pernicious anemia. The patient now has two separate problems requiring urgent investigation for the source of bleeding.

How to Approach the Question

First, identify the negative word in the question: 'not'. This means you are looking for the option that does not fit.
Next, define the central concept: 'pernicious anaemia'. Recall or deduce that this is a specific type of anemia caused by a lack of intrinsic factor, leading to vitamin B12 deficiency and macrocytic red blood cells.
Evaluate each option against this definition:
Does 'Lack of intrinsic factor' cause pernicious anemia? Yes, it's the definition. So, this is not the answer.
Does 'Chronic alcoholism' cause it? It can cause B12 deficiency, so it's related. Keep evaluating.
Does 'Long term use of certain antibiotics/drugs' cause it? Yes, some drugs impair B12 absorption. Also related.

Concept Tested & Keywords

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