Immunology & Metabolic

Question 1

Allergy tests: uses
- skin prick (1)
- radioallergosorbent test (RAST)
- skin patch (1)
- when to use RAST over the others? (1)

Answer 1

• food allergies, pollen
• determines IgE that reads, useful for foods, inhales allergens (e.g. Pollen), wasp/bee
• contact dermatitis
• RAST can be used in anaphylaxis/ extensive eczema/ patient taking antihistamines

Question 2

Anaphylaxis:
- initial management? (dose+time) (3)
- management of refractory? (1)

Answer 2

• IM adrenaline every 5 mins
• 500 micrograms
• IV adrenaline infusion AFTER 2 doses of IM

Question 3

Adrenaline doses
- <6 months
- 6m - 6years
-6-12years
- >12 years

Answer 3

• 100-150 micrograms
• 150 micrograms
• 300 micrograms
• 500 micrograms (0.5 ml of 1 in 1,000)

Question 4

Allergy tests:
- skin prick test control? (1)
- skin prick when to read? (1)
- skin patch when to read? (1)
- RAST how does it work? (1)

Answer 4

• histamine
• after 15-20 mins
• 48 hr
• IgE

Question 5

Most useful test to determine anaphylaxis

Answer 5

serum tryptase

Question 6

Hyponatraemia:
- causes of pseudohyponatraemia? (2)
- if urinary sodium >20? if hypovolaemic (3) and euvolaemic (2)
- if sodium <20?

Answer 6

• hyperlipidaemia
• taking blood from drip arm

Sodium >20
HYPOVOLAEMIC
- diuretics, Addisons, diuretic stage of renal failure
EUVOLAEMIC
- SIADH, hypothyroid

Sodium <20
- diarrhoea, vomiting, sweating
burns, adenoma of rectum
water excess, psychogenic polydipsia

Question 7

SIADH and cancer?

Answer 7

small cell lung cancer
(also pancreas and prostate)

Question 8

SIADH:
- cancer (1)
- neurological (4)
- infectious (2)
- drugs (5)
- other (2)

Answer 8

• SCLC
• stroke
• SAD
• sub dural
• meningitis/ encephalitis/ abscess
• TB
• pneumonia
• sulfonylureas
• SSRIs, tricyclics
• carbamazepine
• vincristine
• cylophosphamide
• positive end-expiratory pressure
• prophyrias

Question 9

SIADH
- investigations (2)
- management (4)

Answer 9

• urine osmolality
• urine sodium concentration
• slow correction (pontine myelinolysis)
• fluid restrict
• demeclocycline
• ADH vasopressin receptor antagonist

Question 10

raised ALP and normal LFTs?
- raised calcium (2)
- low calcium (2)

Answer 10

• bone cancer/ mets
  or hyperparathyroidism
• osteomalacia or renal failures

Question 11

statins and pregnancy

Answer 11

discontinue for 3 months before conception and during pregnancy

Question 12

who gets high statin therapy (80mg) (3)

Answer 12

IHD, stroke, PVD

Question 13

Hypocalaemia
- features? (4)
- Trousseau/ Chvosteks (2)

Answer 13

• tetany: muscle twitching, cramping and spasm
• perioral paraesthesia
• if chronic: depression, cataracts
• ECG: prolonged QT interval
• carpal spasm + wrist flexion
• tapping over parotid causes pain

Question 14

ECG hyperkalaemia

Answer 14

tall-tented T waves, small P waves, widened QRS leading to a sinusoidal pattern and asystole

Question 15

Hyperkalaemia:
- causes? (7)

Answer 15

acute kidney injury
drugs*: potassium sparing diuretics, ACE inhibitors, angiotensin 2 receptor blockers, spironolactone, ciclosporin, heparin**
metabolic acidosis
Addison’s disease
rhabdomyolysis
massive blood transfusion

Question 16

Management hyperkalaemia:
- initial? (1)
- delayed effect (2-3 days)? (1)
- other (2)

Answer 16

• IVF
• bisphosphonates
• calcitonin
• steroids for sarcoidosis

Question 17

Hyperlipidaemia:
- diagnosis? (2)

Answer 17

• a total cholesterol level greater than 7.5 mmol/l

AND/ OR

• a personal or family history of premature coronary heart disease (an event before 60 years in an index individual or first-degree relative)

Question 18

Deficiencies:
- B1 (2)
- B3 (niacin) (3)

Answer 18

• polyneuropathy
• Wernicke-Korsakoff syndrome
• heart failure

pellegra
- dementia
- dairrhoea
- dermatitis