inflammatory myopathy

Question 1

what are the three inflammatory myopathies ?

Answer 1

dermatomyositis
polymyositis
inclusion body myositis

Question 2

what is the clinical picture of inflammatory myopathies ?

Answer 2

• insidious onset
• fever and weight loss
• non-erosive inflammatory polyarthritis
• Raynaud’s phenomenon

Question 3

which muscles are mostly affected inn polymyositis and dermatomyositis ?

Answer 3

• proximal muscles of the limb (symmetrical)
  upper and lower limb
  along with affection of the pharyngeal and respiratory muscles

- pharyngeal and respiratory muscle weakness

Question 4

what type of movements would these patients have difficulties performing ?

Answer 4

difficulty getting up from the chair
difficulty combing hair
difficulty climbing stairs

Question 5

what are the skin manifestations in dermatomyositis ?

Answer 5

• heliotrope rash on eyelids
• rash on the face neck and chest ( V sign )
• Rash on back and shoulders ( shawl sign)
• Gottrons papules
• gottrons rash
• mechanics hand
• dilated nail bed capillary loops
• subcut calcifications
• holster sign

Question 6

what are the features of heliotrope rash ?

Answer 6

purple discoloration on the eyelids specific to deermatomyositis

Question 7

what are gottorns papules ?

Answer 7

papules on the MCP that are diagnostic of dermatomyositis

Question 8

what does mechanic hand look like ?

Answer 8

rough and cracked skin on the lateral aspect of index fingers and thumb

Question 9

what type of patients are more likely to have calcinosis ?

Answer 9

juvenile dermatomyositis

Question 10

what is the onset of polymyositis ?

Answer 10

subacute onset

Question 11

what is the clinical presentation of polymyositis?

Answer 11

weakness affecting proximal muscles 
no rash 
dysphagia 
AV conduction defects- arrhythmia 
ILD

Question 12

what lab investigations would we order for a diagnosis of DM or PM ?

Answer 12

turn you muscles into CLAA (clay)
CK
LDH
Aldolase
AST
ALT

Question 13

when can we find CK levels to be normal ?

Answer 13

active dermatomyositis and inclusion body myositis

Question 14

what would we find on EMG ?

Answer 14

increased spontaneous activity and fibrillations

Question 15

what are the differences in PM and DM in muscle biopsy ?

Answer 15

DM: layers of atrophic muscle fibres at the periphery of fascicles is diagnostic
PM: CD8 lymphocytic infiltration ( directed against MHC-1)

Question 16

what is the treatment for inflammatory myopathy ?

Answer 16

1- predinsolone ( very responsive to steroids)
muscle strength usually lags behind improvement in muscle enzymes
2- hydroxychloroquine for dermatomyositis

Question 17

what is the dose for predinsolone given ?

Answer 17

0.5-1.5 mg per kg per day 
then 
reduce by 5mg per week 
then 
reduce by 2.5 mg every 2 weeks

Question 18

what can we give alongside the predinsolone ?

Answer 18

biphosphonate

Question 19

what are the immunosuppressive drugs taken in `pm and Dm

Answer 19

cyclophosphamide 
azathioprine 
mycophenolate mofitil 
cyclosporine 
methotrexate

Question 20

what are the feature of inclusion body myositis ?

Answer 20

affection of males more
only above 50
affection is bilateral but not symmetrical
affection of both distal and proximal muscle affection
non responsive to steroids

Question 21

what does the holster sign show ?

Answer 21

poikiloderma in sun protected areas

Question 22

what is poikiloderma ?

Answer 22

triad of :
tenelgectasia
mottled hypo-hyperpigmentation
atrophy

Question 23

what is the association of dermatomyositis and malignancies ?

Answer 23

lung
breast
colon
ovary

Question 24

what type of respiratory failure would be associated with PM and DM ?

Answer 24

type 2
low oxygen
high co2

Question 25

if the oesophageal muscles or pharyngeal muscles are affected what would the presentation be ?

Answer 25

dysphonia
dysphagia

Question 26

what are the differential diagnosis of proximal symmetrical muscle weakness ?

Answer 26

other than PM and DM
acquired myopathies ( steroid induced , statin induced and with thyroid disease )

Question 27

to obtain a definitive diagnosis of PM orr DM ?

Answer 27

muscle biopsy

Question 28

how would you differentiate between polymyositis and polymyalgia ?

Answer 28

both present with proximal muscle weakness
polymyositis is associated with pain
polymyalgia is associated with stiffness