Anaemia, megaloblastic

D53.1

• Description
• Diagnostic criteria
• General and supportive measures
• Medicine treatment
• Referral

DESCRIPTION

Anaemia caused by a deficiency of folate and/or vitamin B12 .

DIAGNOSTIC CRITERIA

Clinical

• Pallor and fatigue.
• History of chronic diarrhoea.

Investigations

• Megaloblastic anaemia: elevated MCV (mean corpuscular volume) and MCH (mean corpuscular haemoglobin).
• Macro-ovalocytes on blood smear, hypersegmentation of neutrophils.
• Decreased serum vitamin B12 or red blood cell folate.
• Investigations to identify reason for folate or B12 deficiency, e.g. malabsorption.
• Pancytopaenia in severe cases.
• Actively exclude leukaemia and aplastic anaemia which may cause macrocytosis.

GENERAL AND SUPPORTIVE MEASURES

• Dietary modifications to ensure adequate intake of folate and vitamin B12 .
• Packed red blood cell transfusion for symptomatic anaemia. Try to avoid blood transfusion until all investigations have been done.

MEDICINE TREATMENT

Folic acid deficiency:

• Folic acid, oral, 5 mg daily until haemoglobin returns to normal value for age.
  Prolonged treatment may be needed for malabsorption states and congenital deficiencies.

Vitamin B12 deficiency:

• Vitamin B12 , IM, 500 mcg monthly. Should be given together with folate to prevent developmental of subacute combined degeneration of spinal cord. Prolonged treatment may be needed.

REFERRAL

• All cases of megaloblastic anaemia, except clear nutritional folate deficiency.