Iron deficiency anaemia

Question 1

What is iron deficiency anaemia?

Answer 1

Diminished RBCs production due to low iron stores in the body

The most common cause of microcytic anaemia, hypochromic anaemia

Question 2

What investigations are important to do in iron deficiency anaemia?

Answer 2

Bloods
FBCs
- MCV = reduced
- MCH = reduced

Blood film
Small (microcytic) and pale (hypochromic) red cells

Question 3

What level of Hb in men aged over 15 is considered to be anaemia?

Answer 3

Below 130g/L

Question 4

What level of Hb in non-pregnant women aged over 15 is considered to be anaemia?

Answer 4

Below 120g/L

Question 5

What level of Hb in children aged 12-14 years is considered to be anaemia?

Answer 5

Below 120g/L

Question 6

What level of Hb in pregnant women is considered to be anaemia?

Answer 6

Below 110g/L throughout pregnancy

An Hb level of 110 g/L or more appears adequate in the first trimester, and a level of 105 g/L appears adequate in the second and third trimesters

Question 7

What level of Hb in postpartum women is considered to be anaemia?

Answer 7

Below 100g/L

Question 8

Which serum ferritin level is confirms iron deficiency?

Answer 8

less than 30 micrograms/L

Question 9

What are the causes of IDA?

Answer 9

Dietary deficiency

Malabsorption - coeliac disease, gastrectomy, H. pylori, oesophagitis, schistosomiasis or hookworm, or IBD

Increased loss - GI blood loss (can be cause by aspirin, NSAIDs, bowel cancer, benign gastric ulceration, or angiodysplasia), menstruation (most common cause in premenopausal women), other gynae causes are haemorrhage in childbirth

Increased requirement - 3 times higher in pregnancy than in menstruating women, demand increases as pregnancy advances

Other causes - e.g., blood donation, self-harm, haematuria (rare), nosebleeds (rare), medication

Question 10

What is the prevalence of IDA?

Answer 10

500 million people globally

Prevalent in low income populations e.g., sub-Saharan Africa or South Asia

IDA significant problem in developed world - prevalence of 2-% among adult men and postmenopausal women, and it is the reason for 4-13% of referrals to gastroenterologists

Higher incidence of IDA in women in childbearing years - due to loss via menstruation and pregnancy

Global prevalence of anaemia is estimated to be 38% in pregnant women and 29% in non-pregnant women

UK prevalence of anaemia estimated to be 23% in pregnant women and 14% in non-pregnant women

Question 11

What are the complications of IDA?

Answer 11

Cognitive and behavioural impairment in children - especially attention deficits

Impaired muscular performance - endurance, and reduced exercise capacity

HF - high-output HF can occur in people with severe anaemia, especially in those with a Hb level less than 50g/L

Adverse effects on immune status and morbidity from infection (for all age groups)

Question 12

What are the complications of IDA in pregnancy?

Answer 12

Increased morbidity for the mother and infant, and the possibility of LBW

Preterm delivery - increased risk of preterm delivery and perinatal mortality

Maternal postpartum fatigue, altered cognition and depressive symptoms - this in turn may affect the woman’s interactions with the infant and may negatively impact behaviour and development

Infant IDA in the 1st 3 months of life

Question 13

What questions should you ask when taking a detailed medical Hx of someone with suspected IDA?

Answer 13

Sx of anaemia

Diet

DHx - e.g., use of aspirin, NSAIDs, SSRIs, clopidogrel, or corticosteroids

FHx of
- IDA
- bleeding disorders and telangiectasia
- colorectal carcinoma
- haematological disorders (e.g., thalassaemia)
- GI disorders

Hx of overt bleeding, heavy bruising or blood donation

Hx of recent illness which could suggest underlying GI bleeding

Menstrual Hx, pregnancy or breastfeeding (if appropriate)

Travel Hx (increased risk of hookworm in travellers to the tropics)

Weight loss

Question 14

Name very common symptoms of IDA

Answer 14

Dyspnoea

Fatigue

Headache

Question 15

Name common symptoms of IDA

Answer 15

Cognitive dysfunction

Restless leg syndrome

Question 16

Name rare symptoms of IDA

Answer 16

Dysphagia

Haemodynamic instability

Syncope

Question 17

Name other symptoms of IDA

Answer 17

Dizziness or light-headedness

Weakness

Dysgeusia - feeling that all foods taste sour, sweet, bitter or metallic

Irritability

Palpitation

Pica (abnormal dietary cravings, e.g., ice or dirt)

Pruritus

Sore tongue

Tinnitus

Impairment of body temp regulation (in pregnant women)

Question 18

Which symptoms are unlikely unless the Hb level is < 70g/L?

Answer 18

Anginal pain

Ankle oedema

Dyspnoea

Angina may occur if there is pre-existing coronary artery disease

Question 19

Which symptoms of iron deficiency may occur without anaemia?

Answer 19

Fatigue

Lack of concentration

Irritability

Question 20

What are common or very common signs of iron deficiency?

Answer 20

Pallor - may be observed even with mild anaemia

Atrophic glossitis

Dry and rough skin, dry and damaged hair

Diffuse and moderate alopecia

Question 21

Name other signs of iron deficiency

Answer 21

Angular cheilosis (ulceration of the corners of the mouth)

Nail changes - e.g., longitudinal ridging and koilonychia (spoon-shaped nails)

Worsening of pre-existing tachycardia, murmurs, cardiac enlargement and HF may occur if anaemia is severe (Hb < 70g/L)

There could also be no signs even though the patient has severe anaemia

Question 22

What are the differential diagnosis for IDA?

Answer 22

Thalassaemia

Sideroblastic anaemia (very rare)

Anaemia of chronic disease

Lead poisoning

Thalassaemia and sideroblastic anaemia are both associated with an accumulation of iron, so tests will show and increase in serum iron and ferritin, and a low total iron-binding capacity

Question 23

How would you manage IDA?

Answer 23

65mg elemental iron - ferrous sulphate 200mg OD on an empty stomach

Question 24

Which preparations are not recommended in treating IDA?

Answer 24

Modified-release iron preparations

Preparations that contain iron combined with folic acid, vitamin B12, and other nutrients

Question 25

What monitoring should be done for someone being treated for IDA with iron supplementation?

Answer 25

Check Hb levels within the first 4 weeks of iron supplement Tx

[Hb] should rise by about 20g/L over 3-4 weeks

If there is a response check FBC at 2-4 months to ensure Hb level has returned to normal

Question 26

What should you do once the [Hb] and red cell indices are back to normal?

Answer 26

Continue iron Tx for 3 months to aid replenishment of iron stores and then stop

Monitor the person’s FBC periodically - e.g., 3-monthly for 12 months then 6-monthly for 2-3 years

Question 27

In which group of patients would you give ongoing iron supplementation?

Answer 27

Recurring anaemia

Iron-poor diet e.g., vegans

Malabsorption e.g., coeliac disease

Menorrhagia

Hx of gastrectomy

Could also be beneficial in
- pregnant women
- people undergoing haemodialysis

Question 28

When would you refer people with iron deficiency anaemia using a suspected cancer pathway for an appointment within 2 weeks?

Answer 28

If they are aged 60 years or over

Question 29

When you consider an urgent referral for people with iron deficiency anaemia using a suspected cancer pathway for an appointment within 2 weeks?

Answer 29

Aged under 50 years and present with rectal bleeding

Question 30

When would you refer someone with IDA to gastroenterology?

Answer 30

All men and postmenopausal women with iron deficiency anaemia unless they have overt non-gastrointestinal bleeding

Men with a Hb level less than 120 g/L and postmenopausal women with an Hb level less than 100 g/L should be investigated more urgently, as lower levels of Hb suggest more serious disease.

All people aged 50 years or over with marked anaemia or a significant FHx of colorectal carcinoma even if coeliac disease

Premenopausal women if they are aged < 50 years and have colonic symptoms, a strong FHx of GI cancer, persistent IDA despite Tx, or if they do not menstruate (e.g., following hysterectomy)

Question 31

When would you refer women with IDA to gynaecology?

Answer 31

Menorrhagia unresponsive to med Mx

PMB
- for women aged > 55 years - refer urgently using a suspected cancer pathway for an appointment within 2 weeks
- for women aged < 55 years - consider referring urgently using a suspected cancer pathway for an appointment within 2 weeks

Pregnant & has significant symptoms and/or severe anaemia (Hb < 70g/L) or late gestation (> 34 weeks), or if there is failure to respond a trial or oral iron

Question 32

When else would refer people with IDA?

Answer 32

+ve coeliac serology

profound anaemia with signs of HF

unable to tolerate, or are not responding to, oral Tx

Initially responded to iron Tx but develop anaemia again without an obvious underlying cause

When the type of anaemia is in doubt

When further haematological Ix, e.g., bone marrow examination or an Ix of bleeding state, cannot be carried out in primary care

Question 33

Why type to anaemia should you consider when microcytic anaemia is non-responsive to iron replacement?

Answer 33

Sideroblastic anaemia

condition is characterized by
ineffective erythropoiesis, leading to reduced iron absorption, iron loading in marrow ± haemosiderosis
(endocrine, liver, and heart damage due to iron deposition).

Question 34

What % of older people with MCV <75fL are not iron deficient?

Answer 34

20%

Question 35

Sources

Answer 35

https://cks.nice.org.uk/topics/anaemia-iron-deficiency/management/management/#iron-supplements

https://bnf.nice.org.uk/drugs/ferrous-fumarate/

pg 326 Oxford Handbook of Clinical Medicine 10th ed