Rheumatology 2

Question 1

Hypersensitivity

State the mechanism and examples for the following hypersensitivity reactions

1. Type I
2. Type II
3. Type III
4. Type IV
5. Type V

Answer 1

1. IgE bound to mast cells reacts to antigen
   e. g. anaphylaxis or atopy
2. IgM / IgG binds to antigen
   e. g. mnemonic: A Good PARP
   - autoimmune haemolytic anaemia
   - good pasture’s syndrome
   - pernicious anaemia
   - acute haemolytic transfusion reactions
   - rheumatic fever
   - pemphigus vulgaris / bullous pemphigoid
3. antigen + antibody combine
   e. g.
   - post-strep glomerulonephritis
   - extrinsic allergic alveolitis (acute phase)
   - SLE
4. T cell mediated (delayed hypersensitivity)
   e. g. delayed in the SENAT because they’re all lazy americans

• Scabies
• extrinsic allergic alveolitis (chronic)
• Neuro: guillain-barre, MS
• allergic dermatitis
• TB

5. antibodies that bind to cell surface receptors
   e. g. Graves, myasthenia gravis

Question 2

What should you suspect in bine pain with cutaneous nodules and recurrent otitis media?

Answer 2

Langerhan cell histiocytosis

NOTE: tennis racket shaped birbeck granules on electromicroscopy

Question 3

Marfans syndrome

1. Which protein is affected?
2. What clinical features are seen?

Answer 3

1. fibrillin 1 (F1)
2. • valve: aortic regurgitation + mitral valve prolapse
   • aortic aneurysm + dissection (due to dilated aortic sinuses)
   • arachnodactyly (long fingers like a spider)
   • pes planus - flat feet (foot all in the same plane)
   • pectus excavatum
   • dural Ectasia (so will see ballooning of dural sac at lumbosacral level - think CSF all sinks to bottom)
   • eye: upward lens dislocation

mnemonic: never driving in F1 because they’re tall and VAAPPEE

Question 4

Methotrexate

1. What are its SEs?
2. What is the advice re pregnancy?
3. What are the drug interactions of note?
4. What should be co-prescribed?

Answer 4

1. • myelosuppression
   • mucositis
   • liver fibrosis
   • lung: pneumonitis, pulmonary fibrosis
2. avoid pregnancy and take contraception 6 months after treatment has stopped
3. • trimethoprim / co-trimoxazole: increased bone suppression
   • aspirin: decreased excretion
4. folic acid - taken >24hrs after dose

NOTE: both folic acid and methotrexate taken weekly

Question 5

1. What should you suspect in a child presenting with fractures following minor trauma?
2. What else can be seen in this disease?
3. What is seen on bloods?

Answer 5

1. osteogenesis imperfecta
2. • deafness secondary to otosclerosis
   • dental imperfections
3. normal

Question 6

Osteomalacia

1. What is it?
2. What can cause it?
3. What clinical features are seen?
4. What is seen on investigation?
5. How is it treated?

Answer 6

1. softening of the bones due to low vitamin D

AKA rickets in children

2. • vit D deficiency: malabsorption, diet, lack od sunlight
   • CKD
   • drugs e.g. anticonvulsants
3. • bone pain / tenderness
   • fractures - especially of femoral neck
   • proximal myopathy may lead to waddling gait
4. bloods:
   - low vit D
   - raised ALP
   +/- low Ca and phosphate
5. vit D supplementation (duh)

Question 7

Osteoporosis assessment

1. What should be done in fragility fracture if patient
   a) <75
   b) >75
2. How does this change if patient also taking corticosteroid?

Answer 7

1. a) DEXA scan with FRAX assessment to determine fracture risk

b) straight onto bisphosphonate
2. age moves down to 65

NOTE: if <65 T score

Question 8

DEXA scan

1. What is a T score?
2. What is the diagnosis in a T score of:
   a) -1.0
3. What is a Z score?

Answer 8

1. bone mass assessment in comparison to that of young population
2. a) osteoporosis
   b) osteopenia
   c) normal bone
3. bone score adjusting for age, ethnicity and sex

Question 9

Osteoporosis management

1. What is first line?
2. What should be given if this is not tolerated?
3. What is 3rd line?

Answer 9

1. alendronate
2. risedronate or etidronate
3. strontium ranelate or raloxifene

Question 10

How is Raynaud’s managed?

Answer 10

CCBs e.g. nifedipine

Question 11

Polyarteritis nodosa

1. What is it?
2. Who is it most common in?
3. What clinical features are seen?

Answer 11

1. medium vessel vasculitis
2. middle aged men with Hep B
3. • arthralgia
   • general: fever, malaise, weight loss
   • livedo reticularis
   • testicular pain
   • mononeuritis multiplex / sensorimotor polyneuropathy
   • haemturia / renal failure

Question 12

Sulfasalazine

1. If someone is allergic to this drug what are they also likely to be allergic to and vice-versa?
2. What are some of its side effects?
3. Is it safe to use in pregnancy?

Answer 12

1. • aspirin
   • sulfonamides e.g. co-trimoxazole
2. • oligospermia
   • anaemias + myelosuppression
   • stained tears
3. yes

Question 13

Still’s disease

1. What is it?
2. What age group is it most common in?
3. What clinical features are seen?
4. What is seen on bloods?

Answer 13

1. periodic inflammatory arthritis often affecting the wrists
2. 15-25 and 35-46
3. • arthralgia
   • salmon-pink, maculopapular rash
   • pyrexia: typically rising late afternoon/evening along with the other symptoms
4. elevated serum ferritin

rheumatoid factor and ANA are negative