How can I differentiate between aplastic anaemia and other causes of bone marrow failure in a primary care setting?

In a primary care setting, definitive differentiation between aplastic anaemia and other causes of bone marrow failure is not possible, as this requires specialist investigations ¹ (Marsh et al., 2009; DeZern and Churpek, 2021). The role of primary care is primarily to recognise the potential signs of bone marrow failure and facilitate urgent referral to haematology (Marsh et al., 2009; DeZern and Churpek, 2021).

Key indicators that may prompt suspicion of bone marrow failure include:

• Symptoms of anaemia: Patients may present with fatigue, pallor, or shortness of breath, which are common symptoms of low red blood cell counts (Marsh et al., 2009). While iron deficiency anaemia is a common cause of anaemia ²,³, unexplained or severe anaemia warrants further investigation.
• Increased susceptibility to infections: Frequent or severe infections, particularly bacterial or fungal, can indicate a low white blood cell count (neutropenia) (Marsh et al., 2009).
• Bleeding or bruising: Easy bruising, petechiae, nosebleeds, or prolonged bleeding from minor cuts may suggest a low platelet count (thrombocytopenia) (Marsh et al., 2009).

If these symptoms are present, a full blood count (FBC) is the crucial initial investigation in primary care (Marsh et al., 2009; DeZern and Churpek, 2021). The hallmark of bone marrow failure, including aplastic anaemia, is pancytopenia, which is a reduction in all three major blood cell lines: red blood cells, white blood cells, and platelets (Marsh et al., 2009; DeZern and Churpek, 2021). Other causes of pancytopenia, such as myelodysplastic syndromes, severe megaloblastic anaemia, or certain viral infections like parvovirus B19, would also need to be considered by specialists ¹ (Marsh et al., 2009; DeZern and Churpek, 2021).

Upon finding unexplained pancytopenia, an urgent referral to a haematologist is essential for further evaluation (Marsh et al., 2009; DeZern and Churpek, 2021). The definitive diagnosis and differentiation from other bone marrow disorders, including aplastic anaemia, typically involve a bone marrow aspiration and biopsy, which is performed in secondary care (Marsh et al., 2009; Barone et al., 2015; DeZern and Churpek, 2021).