11. Iron Deficiency Anaemia

Question 1

What are the clinical signs specific to iron-deficiency anaemia?

Answer 1

• Brittle or spoon-shapped nails (kolinycia)
• Brittle hair / hair loss
• Swollen or sore tongue (Atrophic glossitis)
• Cracks or ulcers at the corners of the mouth (‘angular cheilitis’)
• A craving to eat unusual non-food substances such as ice or dirt (known as ‘pica’)
• Restless leg syndrome

Question 2

What are the main 4 circumstances of when we can become deficient in iron?

Answer 2

• Insufficient dietary iron
• Increased iron requirement
• Loss of iron from the body
• Inadequate absorption of iron

Question 3

Who commonly suffers from insufficient dietary iron?

Answer 3

• Vegans / vegetarians
• Children (particularly if diet is low on red meat)
• Pregnant women

Question 4

When may you have an increased iron requirement? Other than anaemia, what happens if they don’t get enough?

Answer 4

In pregnancy.

Lack of iron in a pregnant women can lead to low birth weights and premature delivery. Babies who are taking milk from iron-deficiency anaemic mothers tend to develop iron deficiency anaemia as well

Question 5

When may you have a loss of iron from the body?

Answer 5

In older individuals - suspect a slow bleed from a cancer (especiaally caecal / colon)

In pre-menopausal women - suspect mennorhagia

Question 6

When may you have inadequate iron absorption?

Answer 6

Certain conditions that cause inflammation of the duodenum or jejunem;

• Coeliacs
• Chrons
• Achlorhydria
• Previous surgery to remove part of the stomach or small bowel

Question 7

Why does ulcerative collitis not cause iron-deficiency anaemia?

Answer 7

This is because iron is mainly absorbed in the duodenum and jejunem, and not the large bowel

Question 8

What is Achorhydria? Why does it cause iron-deficiency?

Answer 8

This is when there is a lack of stomach acid. This causes iron-deficiency because the acid keeps the iron in the soluble ferrous form (Fe2+) where it can be absorbed. If not, it turns to Fe3+, which cannot be absorbed.

Question 9

Where is iron absorbed along the GI tract? What is required for this? Why?

Answer 9

Iron is mainly absorbed in the duodenum and jejunum. It requires the acid from the stomach to keep the iron in the soluble ferrous (Fe2+) form. When the acid drops it changes to the insoluble ferric (Fe3+) form.

Question 10

Which medications interfere with iron absorbtion? Why?

Answer 10

Any medication that reduces stomach acid will interfere with iron absorption (ex. PPIs such as omeprazole and lansoprazole)

Question 11

What is the most common cause of GI tract bleeding?

Answer 11

• Oesophagitis

- Gastritis

Question 12

What are the risk factors for iron deficiency anaemia?

Answer 12

• Pregnancy
• Vegetarian or vegan diet
• Menorrhagia
• Hookworm infestation - it causes frequent blood loss
• Uncontrolled coeliac disease, as it causes inflammation of the small bowel leading to poor absorption of iron
• NSAIDs - they cause gastric and duodenal ulcers which lead to iron deficiency anaemia if untreated

Question 13

What laboratory tests can be used in someone who you suspect of having iron-deficiency anaemia?

Answer 13

• FBC (haemoglobin, haematocrit, platelet count, MCV)
• Red cell distribution width (RDW)
• Reticulocyte count
• Serum iron
• Total iron binding capacity (TIBC)
• Serum ferritin
• Transferrin saturation
• H. pylori
• Urine dipstick
• Blood film

Question 14

What would you expect the haemoglobin levels to be like if someone was iron-deficient?

Answer 14

Low levels of haemoglobin will establish the presence of iron-deficiency anaemia.

However, anaemia is a late manifestation of iron deficiency. Hb may be normal to start with but falls off as the disease progresses.

Question 15

What would you expect the platelet count to be like in someone with iron-deficency anaemia?

Answer 15

This is typically normal, however it may be high if there is bleeding going on

Question 16

What would you expect the MCV to be like in someone with iron-deficency anaemia?

Answer 16

Iron deficiency anaemia shows microcytic anaemia. If the MCV is greater than 95 fL, then it rules out iron deficiency as the cause of any anaemia

Question 17

What is red cell distribution width?

Answer 17

This shows the degree of variation in the size of red blood cells.

It has a high sensitivity, but low specificity for iron-deficiency anaemia as it also increases in thalassaemia.

Question 18

What would you expect red cell distribution width to be like in someone with iron-deficiency anaemia?

Answer 18

It increases in iron deficiency anaemia and presents quicker than changes in MCV.

Question 19

What would you expect the reticulocyte count to be like in someone with iron-deficency anaemia?

Answer 19

Reticulocytes are low as there is not sufficient iron to produce red blood cells

Question 20

What would you expect the serum iron level to be like in someone with iron-deficency anaemia? Why is it not done that much?

Answer 20

Measures the amount of iron bound to transferrin. It varies a lot (higher in the morning, higher after meals and during infection) therefore is not that useful on its own. Patient needs to be fasted for this.

Question 21

What is total iron binding capacity?

Answer 21

It is the total space available on ferritin molecules for iron to bind to.

Question 22

What is ferritin? What would low serum levels suggest?

Answer 22

Ferritin is how iron is stored in cells. Low serum levels indicate iron-deficiency

Question 23

What is transferrin saturation? How is it calculated? What percentage is normal?What percentage indicates iron-deficiency anaemia?

Answer 23

It is the percentage of iron-binding sites on ferritin molecules that have iron bound to it.

Transferrin Saturation = Serum Iron / Total Iron Binding Capacity. It is more reliable than either of these as it minimises the effect of an error in either of them.

Normal is around 30%, and if below 16% it indicates iron-deficiency anaemia. It can temporarily increase after taking in iron so a fasting sample gives the best result.

Question 24

Why is H. pylori tested in those with suspected iron deficiency anaemia?

Answer 24

This is because if positive, it may have caused an ulcer, which could be the cause for the anaemia.

Question 25

What should you do next if a H. pylori test comes back positive in someone with suspected iron-deficiency anaemia?

Answer 25

You should then do a urease breath test which is diagnostically confirm it.

You can then also do an OGD to look at the ulcer, if present.

Question 26

Why do a urine dipstick in someone with suspected iron-deficiency anaemia?

Answer 26

You can check for blood loss from the renal tract

Question 27

What might you look for in a blood film if you were to do it on someone with suspected iron-deficiency anaemia?

Answer 27

early on, the RBCs may have a normal size and color (normocytic, normochromic) but as the anaemia progresses, the RBCs become smaller (microcytic) and paler (hypochromic) than normal.

Question 28

What determines the colour of a red blood cell?

Answer 28

The concentration of haemoglobin in it. The paler it is, the less Hb there is.

Question 29

If after the initial investigations for suspected anaemia there is no obvious cause, what should you do?

Answer 29

Colonoscopy / OGD as there may be a slow bleed from a GI cancer.

Be suspicious of this in all men (without history of obvious bleed in other area than GI tract) and post-menopausal women (>50 y/o)

Question 30

What further investigations can you do for someone with iron-deficiency anaemia?

Answer 30

• Colonoscopy / OGD
• Small bowel biopsy
• Bone marrow biopsy
• Autoimmune gastritis testing
• Urease breath test

Question 31

When would you perform a small bowel biopsy on someone with iron deficiency anaemia? Why?

Answer 31

This is advised during OGD. It is done in order to try work out what condition is going on (and therefore why there is an iron deficiency), for example this could be Chrohns.

However, if you see a large bleed, then it’s not that useful to perform a biopsy as you probably already know the cause of the iron deficiency anaemia

Question 32

What does autoimmune gastritis testing involve? What condition does it indicate if positive?

Answer 32

You test for the presence of anti-parietal cell antibodies or intrinsic factor antibodies.

If positive, it indicates pernicious anaemia.

Question 33

When may you see increased ferritin in the blood?

Answer 33

It is released when there is inflammation, therefore in;

• Infection
• Cancer

A lot of iron is stored in the liver as well, so it increases if there is acute liver damage.

It can also, although less likely, be from iron overload

Question 34

Does a normal ferritin level rule out iron-deficiency anaemia?

Answer 34

No, because their low level may be raised by an ongoing infection or cancer.

Question 35

How constant is someones serum iron levels?

Answer 35

It varies significantly throughout the day, with higher levels in the morning and after eating iron containing meals

Question 36

What is the normal range for serum ferritin?

Answer 36

41-400 ug/L

Question 37

What is the normal range for serum iron?

Answer 37

12 – 30 μmol/L

Question 38

What is the normal range for total iron binding capacity?

Answer 38

45 – 80 μmol/L

Question 39

What is the normal range for transferrin saturation?

Answer 39

15 – 50%

Question 40

What is the first management option for iron-deficiency anaemia? When would you do it?

Answer 40

Oral iron supplements. Ex. Ferrous sulfate 200mg three times daily.

This slowly corrects the iron deficiency, but is suitable if the anaemia is not too bad.

Question 41

What are the complications of ferrous sulfate?

Answer 41

• Constipation

- Black coloured stools

Question 42

When is oral ferrous sulfate unsuitable to treat iron deficiency anaemia?

Answer 42

• When malabsoption is the cause of the anaemia
• If the deficiency is severe
• If they are unable to swallow a tablet

Question 43

If the response to oral ferrous sulfate is poor, what 2 options do you have in treating the iron-deficiency?

Answer 43

1) Prescribe ascorbic acid to be taken as well. This increases acidity, keeping the iron in the Fe2+ form where it can be more easily absorbed.
2) Move up onto the next step of the management plan, which is an iron infusion.

Question 44

What is the next line of treatment if oral iron supplementation is inapproriate?

Answer 44

Iron infusion (Ex. Cosmofer) will quickly correct the iron deficiency

Question 45

What is Cosmofer

Answer 45

It is an example of a drug used for iron infusions.

Question 46

What is the complication of an iron infusion? When should it be avoided?

Answer 46

• Very small risk of anaphylaxis

- It should be avoided during sepsis as iron “feeds” bacteria

Question 47

When correct iron deficiency anaemia with iron tablet supplementation, by how much can you expect the haemoglobin levels to rise?

Answer 47

Haemoglobin should rise by about 10 g/L per week.