Anemias

Ref: Davidson 23rd; P- 941

Answer: C
Explanation: Chronic blood loss, particularly from the gastrointestinal tract or menstruation, is the most common cause of iron deficiency anaemia worldwide. Davidson highlights that iron deficiency leads to decreased haemoglobin synthesis and microcytic, hypochromic anaemia. Harrison further emphasises that iron deficiency is more prevalent in low-income countries due to dietary insufficiency and parasitic infections.

Explanation: Iron deficiency anaemia is the most common type of anaemia worldwide. A thorough gastrointestinal history is important, looking in particular for symptoms of blood loss. Menorrhagia is a common cause of anaemia in pre-menopausal females, so women should always be asked about their periods

Ref: Davidson 23rd; P-946, box: 23.36

Ref: Davidson 23rd; P- 924 (Fig-23.10)

Ref: Davidson 23rd; P-954, box - 23.40

Ref: Davidson 23rd; P-949 (Box-23.38)

Variations in red cell size is called anisocytosis.

Ref: Davidson 23rd; P- 921(Box-23.2)

Reference: Davidson 23rd, Fig-23.17

Stem Breakdown:

Fatigue, pallor, and heavy menstrual periods: These symptoms suggest anaemia, and the history of heavy periods (menorrhagia) suggests blood loss as a likely cause.
Haemoglobin of 8.5 g/dL and MCV of 70 fL: The low haemoglobin indicates anaemia, and the low MCV (microcytosis) is characteristic of iron deficiency anaemia.
Option Analysis:

A) Iron deficiency anaemia: This is the correct diagnosis. Davidson and Harrison explain that iron deficiency anaemia is the most common cause of anaemia worldwide and is often due to chronic blood loss, particularly from menstruation in women. The microcytic, hypochromic anaemia (low MCV) is a hallmark finding.
B) Vitamin B12 deficiency: Vitamin B12 deficiency causes macrocytic anaemia (high MCV), not microcytic anaemia. Symptoms include neurological deficits, such as paraesthesia and balance problems, which are absent in this case.
C) Aplastic anaemia: Aplastic anaemia presents with pancytopenia (low red cells, white cells, and platelets) and a hypocellular bone marrow. It does not cause microcytosis and is not related to blood loss from menstruation.
D) Haemolytic anaemia: Haemolytic anaemia causes normocytic or macrocytic anaemia with increased reticulocytes and evidence of haemolysis (e.g., elevated bilirubin, LDH). There is no evidence of haemolysis in this case, and the low MCV points to iron deficiency.

Explanation: Iron deficiency anaemia is the most common type of anaemia worldwide.

Reference: Davidson 23rd; P-137

Ref: Davidson 23rd; P-944, box: 23.32

Reference: Davidson 23rd, Box-3.4

Stem Breakdown:

Fatigue, easy bruising, and frequent nosebleeds: These symptoms suggest bone marrow failure, leading to anaemia (fatigue), thrombocytopenia (bruising, nosebleeds), and possibly leukopenia.
Pancytopenia and hypocellular bone marrow: Pancytopenia (low red cells, white cells, and platelets) with a hypocellular bone marrow is characteristic of aplastic anaemia.
Option Analysis:

A) Aplastic anaemia: This is the correct diagnosis. Davidson and Harrison describe aplastic anaemia as a condition in which the bone marrow fails to produce sufficient blood cells, leading to pancytopenia. The bone marrow is hypocellular (decreased cell production), and the condition can be caused by autoimmune factors, infections, or exposure to toxins.
B) Acute myeloid leukaemia (AML): AML presents with pancytopenia and blasts in the blood or bone marrow, but it is associated with hypercellular bone marrow filled with malignant cells, not hypocellularity.
C) Immune thrombocytopenic purpura (ITP): ITP causes isolated thrombocytopenia (low platelet count), leading to easy bruising and bleeding. However, it does not cause anaemia or leukopenia, and the bone marrow is typically normal or shows increased megakaryocytes.
D) Myelodysplastic syndrome (MDS): MDS can cause pancytopenia, but the bone marrow in MDS is usually hypercellular with abnormal maturation of blood cells, not hypocellular.