General Knowledge

Question 1

Gell and Coombs Hypersensitivity Type 1 (Anaphylactic)

Answer 1

Antigen reacts with IgE bound to mast cells
• Anaphylaxis
• Atopy (e.g. asthma, eczema and hayfever)

Question 2

Gell and Coombs Hypersensitivity Type 2 (Cell Bound)

Answer 2

IgG or IgM binds to antigen on cell surface	
• Autoimmune haemolytic anaemia
• ITP
• Goodpasture's syndrome
• Pernicious anaemia
• Acute haemolytic transfusion reactions
• Rheumatic fever
• Pemphigus vulgaris / bullous pemphigoid

Question 3

Gell and Coombs Hypersensitivity Type 3 (Immune Complex)

Answer 3

Free antigen and antibody (IgG, IgA) combine
• Serum sickness
• Systemic lupus erythematosus
• Post-streptococcal glomerulonephritis
• Extrinsic allergic alveolitis (especially acute phase)

Question 4

Gell and Coombs Hypersensitivity Type 4 (Delayed Hypersensitivity)

Answer 4

T-cell mediated	
• Tuberculosis / tuberculin skin reaction
• Graft versus host disease
• Allergic contact dermatitis
• Scabies
• Extrinsic allergic alveolitis (especially chronic phase)
• Multiple sclerosis
• Guillain-Barre syndrome

Question 5

Gell and Coombs Hypersensitivity Type 5

Answer 5

Antibodies that recognise and bind to the cell surface receptors.

This either stimulating them or blocking ligand binding • Graves’ disease
• Myasthenia gravis

Question 6

Mesenteric Ischaemia

Answer 6

Predisposing factors

• increasing age
• atrial fibrillation
• other causes of emboli: endocarditis
• cardiovascular disease risk factors: smoking, hypertension, diabetes
• cocaine: ischaemic colitis is sometimes seen in young patients following cocaine use

Features

• abdominal pain
• rectal bleeding
• diarrhoea
• fever
• bloods typically show an elevated WBC associated with acidosis

Management

• supportive care
• laparotomy and bowel resection

Question 7

Renal Stone Types

Answer 7

• Calcium oxalate (40%, Opaque)
• Mixed calcium oxalate/phosphate stones (25%, Opaque)
• Triple phosphate stones (10%, Opaque)
• Calcium phosphate (10%, Opaque)
• Urate stones (5-10%, Radio-lucent)
• Cystine stones (1%, Semi-opaque, ‘ground-glass’ appearance)
• Xanthine stones (<1%, Radio-lucent)

Question 8

Charcot’s Triad

Answer 8

Charcot’s triad of right upper quadrant (RUQ) pain, fever and jaundice occurs in about 20-50% of patients with ascending cholangitis.
- Fever is the most common feature, seen in 90% of patients
- RUQ pain 70%
- Jaundice 60%
Hypotension and confusion are also common

Question 9

Vaccinations (live attenuated)

Answer 9

• BCG
• Measles, mumps, rubella (MMR)
• Influenza (intranasal)
• Oral rotavirus
• Oral polio
• Yellow fever
• Oral typhoid

Question 10

Vaccinations (inactivated preparations)

Answer 10

• Rabies

- Influenza (intramuscular)

Question 11

Vaccinations (detoxified exotoxins)

Answer 11

• Tetanus

Question 12

Vaccinations (extracts of the organism)

Answer 12

• Diphtheria
• Pertussis (‘acellular’ vaccine)
• Hepatitis B
• Meningococcus, pneumococcus, haemophilus

Question 13

Third Nerve Palsy Features

Answer 13

• Eye is deviated ‘down and out’
• Ptosis
• Pupil may be dilated (sometimes called a ‘surgical’ third nerve palsy)

Question 14

Addison’s (adrenal insufficiency) Features

Answer 14

• Lethargy, weakness, anorexia, nausea & vomiting, weight loss, ‘salt-craving’
• Hyperpigmentation (especially palmar creases), vitiligo, loss of pubic hair in women, hypotension
• Crisis: collapse, shock, pyrexia

Question 15

Primary Hyperaldosteronism Features

Answer 15

• Hypertension
• Hypokalaemia (e.g. muscle weakness)
• Alkalosis

Question 16

Normal Pressure Hydrocephalus Features

Answer 16

A classical triad of features is seen:

• Urinary incontinence
• Dementia and bradyphrenia
• Gait abnormality (may be similar to Parkinson’s disease)

Question 17

Vitamin A

Answer 17

Retinoids

Night-blindness (nyctalopia)

Question 18

Vitamin B1

Answer 18

Thiamine

Beriberi

• polyneuropathy, Wernicke-Korsakoff syndrome
• heart failure

Question 19

Vitamin B3

Answer 19

Niacin

Pellagra

• dermatitis
• diarrhoea
• dementia

Question 20

Vitamin B6

Answer 20

Pyridoxine

Anaemia, irritability, seizures

Question 21

Vitamin B7

Answer 21

Biotin

Dermatitis, seborrhoea

Question 22

Vitamin B9

Answer 22

Folic acid

Megaloblastic anaemia, deficiency during pregnancy - neural tube defects

Question 23

Vitamin B12

Answer 23

Cyanocobalamin

Megaloblastic anaemia, peripheral neuropathy

Question 24

Vitamin C

Answer 24

Ascorbic acid

Scurvy

• gingivitis
• bleeding

Question 25

Vitamin D

Answer 25

Ergocalciferol, cholecalciferol

Rickets, osteomalacia

Question 26

Vitamin E

Answer 26

Tocopherol, tocotrienol

Mild haemolytic anaemia in newborn infants, ataxia, peripheral neuropathy

Question 27

Vitamin K

Answer 27

Naphthoquinone

Haemorrhagic disease of the newborn, bleeding diathesis

Question 28

Sickle Cell Crises

Answer 28

Thrombotic crises

• also known as painful crises or vaso-occlusive crises
• precipitated by infection, dehydration, deoxygenation
• infarcts occur in various organs including the bones (e.g. avascular necrosis of hip, hand-foot syndrome in children, lungs, spleen and brain)

Sequestration crises

• sickling within organs such as the spleen or lungs causes pooling of blood with worsening of the anaemia
• acute chest syndrome: dyspnoea, chest pain, pulmonary infiltrates, low pO2 - the most common cause of death after childhood

Aplastic crises

• caused by infection with parvovirus
• sudden fall in haemoglobin

Haemolytic crises

• rare
• fall in haemoglobin due an increased rate of haemolysis

Question 29

Peutz-Jeghers Syndrome Features

Answer 29

• AD (responsible gene encodes serine threonine kinase LKB1 or STK11)

Features

• hamartomatous polyps in GI tract (mainly small bowel)
• pigmented lesions on lips, oral mucosa, face, palms and soles
• intestinal obstruction e.g. intussusception
• gastrointestinal bleeding

Question 30

Drugs that must be avoided in pregnancy

Answer 30

• Aspirin
• Sulphonylureas
• Carbimazole
• Ciprofloxacin
• Benzodiazepines
• Lithium
• Sulphonamides
• Tetracyclines
• Amiodarone
• Cytotoxic drugs