Microcytic Anaemia Flashcards
Definition
Anaemia associated with a low MCV (< 80 fl)
Aetiology
• Iron Deficiency - MOST COMMON
o Iron deficiency can be caused by:
• Blood loss (e.g. GI)
• Reduced absorption (e.g. small bowel disease)
• Increased demands (e.g. growth, pregnancy)
• Reduced intake (e.g. vegans)
Overall problem with absorption or blood loss somewhere
• Anaemia of Chronic Disease
o Microcytic anaemia in a patient with chronic disease
• Thalassemia
• Sideroblastic Anaemia
o Abnormality of haem synthesis
o It can be inherited or it can be secondary (e.g. to alcohol, drugs)
Epidemiology
Iron deficiency anaemia is the MOST COMMON form of anaemia worldwide
Can either be:
Iron deficiency anaemia (high transferrin)
Beta thalassaemia
Anaemia of chronic disease (high ferritin and low/normal transferrin)
Presenting symptoms (non-specific)
o Tiredness o Lethargy o Malaise o Dyspnoea o Pallor o Exacerbation of ischaemic conditions (e.g. angina, intermittent claudication)
Presenting symptoms (lead poisoning)
Lead Poisoning - can cause microcytic anaemia
Symptoms of lead poisoning o Anorexia o Nausea/Vomiting o Abdominal pain o Constipation o Peripheral nerve lesions
Signs on physical examination
• Signs of anaemia
o Pallor
o Brittle nails and hair
o Koilonychia (if severe)
- Glossitis
- Angular stomatitis
- Signs of thalassemia
Signs on physical examination (lead poisoning)
Lead poisoning signs: o Blue gumline o Peripheral nerve lesions (causing wrist or foot drop) o Encephalopathy o Convulsions o Reduced consciousness
Investigations (bloods)
o FBC
• Low Hb
• Low MCV
• Reticulocytes
o Serum iron (low in iron deficiency)
o Total iron binding capacity (high in iron deficiency)
o Serum ferritin (low in iron deficiency)
o Serum lead
Transferrin is high in iron deficiency anaemia
Investigations (blood film)
o Iron deficiency anaemia: • Microcytic • Hypochromic • Anisocytosis • Poikilocytosis
o Sideroblastic anaemia:
• Dimorphic blood film
• Hypochromic microcytic cells
o Lead poisoning:
• Basophilic stippling
Investigations (other)
• Hb Electrophoresis
o Checking for haemoglobin variants and thalassemia
• Sideroblastic Anaemia
o Ring sideroblasts in the bone marrow
• Special investigations for iron deficiency anaemia if > 40 yrs and post-menopausal women
These are considered if no obvious cause of blood loss is identified
o Upper GI endoscopy
o Colonoscopy
o Haematuria
Younger people would order upper GI endoscopy first as peptic ulcer common cause
Older people would order colonoscopy as colonic cancer a common cause of bleeding/iron deficiency anaemia
Management plan (iron deficiency anaemia)
Oral iron supplements
Management plan (sideroblastic anaemia)
o Treat the cause
o Pyridoxine used in inherited forms
o Blood transfusion and iron chelation can be considered if there is no response to other treatments
Management plan (lead poisoning)
o Remove the source
o Dimercaprol
o D-penicillinamine
Possible complications
- High-output cardiac failure
* Complications related to the CAUSE
Prognosis
Depends on the CAUSE