Iron deficiency anaemia Flashcards
What is iron deficiency anaemia?
Diminished RBCs production due to low iron stores in the body
The most common cause of microcytic anaemia, hypochromic anaemia
What investigations are important to do in iron deficiency anaemia?
Bloods
FBCs
- MCV = reduced
- MCH = reduced
Blood film
Small (microcytic) and pale (hypochromic) red cells
What level of Hb in men aged over 15 is considered to be anaemia?
Below 130g/L
What level of Hb in non-pregnant women aged over 15 is considered to be anaemia?
Below 120g/L
What level of Hb in children aged 12-14 years is considered to be anaemia?
Below 120g/L
What level of Hb in pregnant women is considered to be anaemia?
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
What level of Hb in postpartum women is considered to be anaemia?
Below 100g/L
Which serum ferritin level is confirms iron deficiency?
less than 30 micrograms/L
What are the causes of IDA?
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
What is the prevalence of IDA?
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
What are the complications of IDA?
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)
What are the complications of IDA in pregnancy?
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
What questions should you ask when taking a detailed medical Hx of someone with suspected IDA?
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
Name very common symptoms of IDA
Dyspnoea
Fatigue
Headache
Name common symptoms of IDA
Cognitive dysfunction
Restless leg syndrome
Name rare symptoms of IDA
Dysphagia
Haemodynamic instability
Syncope
Name other symptoms of IDA
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)
Which symptoms are unlikely unless the Hb level is < 70g/L?
Anginal pain
Ankle oedema
Dyspnoea
Angina may occur if there is pre-existing coronary artery disease
Which symptoms of iron deficiency may occur without anaemia?
Fatigue
Lack of concentration
Irritability
What are common or very common signs of iron deficiency?
Pallor - may be observed even with mild anaemia
Atrophic glossitis
Dry and rough skin, dry and damaged hair
Diffuse and moderate alopecia
Name other signs of iron deficiency
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
What are the differential diagnosis for IDA?
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
How would you manage IDA?
65mg elemental iron - ferrous sulphate 200mg OD on an empty stomach
Which preparations are not recommended in treating IDA?
Modified-release iron preparations
Preparations that contain iron combined with folic acid, vitamin B12, and other nutrients
What monitoring should be done for someone being treated for IDA with iron supplementation?
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
What should you do once the [Hb] and red cell indices are back to normal?
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
In which group of patients would you give ongoing iron supplementation?
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
When would you refer people with iron deficiency anaemia using a suspected cancer pathway for an appointment within 2 weeks?
If they are aged 60 years or over
When you consider an urgent referral for people with iron deficiency anaemia using a suspected cancer pathway for an appointment within 2 weeks?
Aged under 50 years and present with rectal bleeding
When would you refer someone with IDA to gastroenterology?
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)
When would you refer women with IDA to gynaecology?
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
When else would refer people with IDA?
+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
Why type to anaemia should you consider when microcytic anaemia is non-responsive to iron replacement?
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).
What % of older people with MCV <75fL are not iron deficient?
20%
Sources
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
