Pernicious Anaemia

Question 1

When should you use pernicious anaemia

Answer 1

• unexplained fatigue
• memory loss
• poor concentration
• paraesthesia

Question 2

What can lead to a missed or delayed diagnosis of pernicious anaemia

Answer 2

• third of patients have normal B12 levels and normocytic anaemia leading to a missed or delayed diagnosis

Question 3

What should screening for patients with suspected pernicious anaemia include

Answer 3

• full blood count

- serum cobalamin assay

Question 4

What is pernicious anaemia

Answer 4

Pernicious anaemia is an autoimmune disorder
affecting the gastric mucosa with impaired absorption
of dietary cobalamin (vitamin B12) resulting in B12
deficiency.

Question 5

What is the B12 essential for

Answer 5

• production of blood cells

- myelination of nerves

Question 6

what does deficiency of B12 cause

Answer 6

• megaloblastic anaemia

- neuronal demyelination

Question 7

How common is pernicious anaemia

Answer 7

between 50-200 per 100000 people in the UK

Question 8

what is pernicious anaemia associated with

Answer 8

• autoimmune thyroiditis
• Addisons disease
• vitiligo
• type 1 diabetes

Question 9

What are the types of pernicious anaemia

Answer 9

General symptoms 
• Tiredness
• Dry skin
• Brittle nails
• Glossitis
• Hair loss or greying

Neurological symptoms 
• Memory loss
• Poor concentration
• Clumsiness
• “Pins and needles” sensation
• Poor sleep
• Confusion
• Dizziness
• Nominal aphasia
• Balance problems

Cardio-respiratory problems
• Shortness of breath
• Palpitations

GI problems 
• Diarrhoea
• Indigestion
• Stomach cramps
• Loss of appetite
• Loss of taste

Question 10

about 20% of patients with pernicious anaemia have a coexisting iron deficiency which can…

Answer 10

About 20% of patients with pernicious anaemia have
coexisting iron deficiency, and the blood film may reveal normocytic
anaemia, or even microcytic anaemia in extreme circumstances, masking the diagnosis of B12 deficiency

Question 11

What is an early manifestations of pernicious anaemia

Answer 11

Peripheral neuropathy is an early neurological manifestation of pernicious anaemia, which causes reversible paraesthesia and numbness.

Question 12

What occurs later in pernicious anaemia

Answer 12

• subacute combined degeneration of the spinal cord occurs in later stages = this can lead to weakness of the limbs and trunk, ataxia, visual defects and autonomic dysfunction

Question 13

what are the red flag complications for pernicious anaemia

• peripheral neuropathy
• subacute combined degeneration of spinal cord
• cardiac failure
• neuropsychiatric manifestation

Answer 13

• peripheral neuropathy = paraesthesia and hyporeflexia
• subacute combined degeneration of spinal cord = ataxic gait, reduce muscle power
• cardiac failure = shortness of breath, peripheral oedema
• neuropsychiatric manifestation = cognitive impairment and depression

Question 14

List the complications for pernicious anaemia

Answer 14

• peripheral neuropathy
• subacute combined degeneration of spinal cord
• cardiac failure
• neuropsychiatric manifestation

Question 15

What can be other causes of B12 deficiency

Answer 15

• vegan diet
• history of ill disease or resection
• total or partial gastrectomy

Question 16

What investigations do you use for pernicious anaemia

Answer 16

• FBC
• blood film
• macrocytes
• hyperhsegmented neutrophils

Question 17

What can cause macrocytosis

Answer 17

• folate deficiency
• liver disease
• alcoholism
• B12 deficiency

Question 18

what test can you use to work out if you have pernicious anaemia

Answer 18

• antibodies to intrinsic factor are highly specific for pernicious anaemia but a negative result does not rule out the disease due to the tests low sensitivity

Question 19

how do you manage pernicious anaemia with no neurological symptoms

Answer 19

• Intramuscular injection of hydroxocobalamin (1000 μg) thrice a week for two weeks
• Maintenance dose—Intramuscular injection once every three months

Question 20

How do you manage pernicious anaemia with neurological symptoms

Answer 20

• Alternate day intramuscular injections of hydroxocobalamin until maximal improvement is noted clinically
• Maintenance dose—Intramuscular injection once every two months

Question 21

with adequate cobalamin replacement…

Answer 21

With adequate cobalamin replacement, reticulocyte count generally increases and peaks at one week, and anaemia and macrocytosis normalise within eight weeks.
- neurological improvement is slower and not as predictable