Anaemia - Folate Deficiency Flashcards
Outline the epidemiology of folate deficiency anaemia (3).
Main demographic:
* Pre-school children
* Pregnant women
* Older people
What are the risk factors of folate deficiency anaemia (6)?
- Low dietary folate intake
- Age > 65 years
- Alcohol-use disorder
- Pregnant or lactating
- Prematurity
- Congenital defects in folate absorption and metabolism
Hx of:
* Intestinal malabsorptive disorders
* Use of trimethoprim, methotrexate, sulfasalazine, pyrimethamine, or anticonvulsants (e.g., phenytoin, phenobarbital)
Outline the pathogenesis of folate deficiency anaemia (9 aetiological reasons, know 4).
Folate intake can be inadequate for various reasons:
* Consumption of unfortified cereals as a staple diet
* Excessive cooking, destroying folate, in green vegetables and legumes
* Poor dietary intake by older people
* Intake of special diets that are low in folate by patients with certain medical conditions, such as phenylketonuria
* Intestinal malabsorption of folate occurs in disorders of the small intestine, such as tropical sprue and coeliac disease (non-tropical sprue), and after extensive intestinal resection.
* Increased demand in pregnancy, lactation, and prematurity can lead to folate deficiency.
* Increased loss of folate occurs in patients undergoing chronic dialysis, and decreased folate is seen in disorders of increased cell turnover, such as chronic haemolytic disease and exfoliative dermatitis.
* Medications including sulfasalazine, trimethoprim, methotrexate, pyrimethamine, and anticonvulsants (e.g., phenytoin, phenobarbital) can cause folate deficiency. Folate deficiency in alcohol-use disorder is caused by multiple mechanisms.
* Hereditary folate malabsorption and other inborn errors of folate metabolism are rare causes of folate deficiency.
Outline the pathophysiology of folate deficiency anaemia (3).
- Both folate and vitamin B12 (cobalamin) are cofactors in methylation of homocysteine to form methionine
- Therefore, deficiency of either vitamin increases homocysteine (a biomarker of folate deficiency)
- NADPH reduces glutathione, which mitigates oxidative stress in rapidly dividing cells.
How would a patient with folate deficiency anaemia present (14)?
Common:
* Prolonged diarrhoea
* Loss of appetite and weight loss
* Fatigue
* Shortness of breath
* Dizziness
* Pallor
* Headache
* Tachycardia
* Tachypnoea
* Heart murmur
* Signs of heart failure
* Signs of chronic alcohol misuse
* Signs of haemolytic anaemia
* Signs of exfoliative dermatitis
Uncommon:
* Painful swallowing
* Petechiae
* Glossitis
* Angular stomatitis
* Neurological deficits in children
Hx of:
* Risk factors
What investigations are recommended in suspected folate deficiency anaemia (3)?
- Peripheral blood smear
- FBC
- Reticulocyte count
What would is the diagnostic result of FBC in folate deficiency anaemia?
- Hb
- MCH
- MCV
- Platelet
- WBC count
- Hb: reduced
- MCH: elevated
- MCV: elevated
- Platelet: normal
- WBC count: normal
What would is the diagnostic result of peripheral blood smear in folate deficiency anaemia?
Macrocytosis, anisocytosis, poikilocytosis, hypersegmented neutrophils
What would is the diagnostic result of reticulocyte count in folate deficiency anaemia?
Low
What is the management of a patient with folate deficiency anaemia at risk of folate deficiency due to pregnancy or lactation (2)?
Oral folic acid + Multivitamin supplementation
What is the management of a patient with folate deficiency anaemia at risk of folate deficiency due to malabsorption disorders, chronic haemolytic disorder, or chronic dialysis (2)?
Oral folic acid + Treatment of underlying disease
What is the management of a patient with folate deficiency anaemia at risk of folate deficiency due to medication (1)?
Folinic acid
