Inflammatory Myopathies - Postlethwaite Flashcards Preview

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Flashcards in Inflammatory Myopathies - Postlethwaite Deck (36):
1

Definition of inflammatory myopathies?

Group of immune mediated disorders with symmetrical proximal muscle weakness and frequent involvement of other organs

2

Inflammatory myopathies affect what type of muscle (smooth, striated, cardiac)?

Striated muscle. That is why upper 1/3 of esophagus can be involved. it's striated

3

2 main disorders associated with inflammatory myopathies?

Dermatomyositis, Polymyositis

4

What lab value is elevated in myositis? (hint: think muscle damage)

CK

5

Besides dermatomyositis and polymyositis, name 4 other inflammatory myopathies?

Antisynthetase syndrome, amyopathic dermatomyositis, Juvenile dermatomyositis, Inclusion body myositis

6

Dermatomyositis body involvement?

Skeletal Muscle, skin

7

Polymyositis body involvement?

Muscle only, not skin

8

Dermatoymyositis and Polymyositis location of muscle involvement? Distinguishes from what other disorder?

DM and PM only have proximal muscle involvement. 

Inclusion body myositis will have distal muscle involvement too. 

9

3 skin findings seen in dermatomyositis?

- Heliotrope rash (rash of the upper eyelids)

- Malar rash

- Gottron papules (red papules on the elbows, knuckles, and knees)

10

Dermatomyositis can be confused with what other disorder? What lab and clinical findings are similar? 

Can be confused with SLE. 

Patient can have +ANA, malar rash

11

What lab finding can help differentiate dermatomyositis from SLE?

+ anti-Jo-1 antibody can be seen in dermatomyositis

12

What 2 disorders are shown here? Which one is which? 

Q image thumb

A = Dermatomyositis; Note the changes on the knuckles and dorsum of the hand (Gottron's sign) 

B = SLE; Rash is absent on the knuckles but present on the phalanges

13

 What is this called?

What syndrome is this associated with?

What antibody is associated with this condition? 

What other symptoms are involved in this syndrome?

Q image thumb

"Mechanic Hands"

seen in Anti-synthetase Syndrome

- anti-Jo-1 antibody

Fever, Arthritis, +/- Raynauds, ILD

"Jo is the F-A-M-IL-y Mechanic"

 

14

Inflammatory myopathies is associated with what pathologic disorders? (just look at the answer. couldnt figure out a way to ask)

12% of myositis cases associated with malignancy (breast cancer, adenocarcinoma)

- DM = 81%, PM = 19% of malignancies

15

CD4+ T cells are associated with what myositis?

Dermatomyositis

16

CD8+ T cells are associated with what myositis?

Polymyositis

17

Biopsy of dermatomyositis will show what? 

Perimysial inflammation (CD4+ T cells) with perifascicular atrophy

----

As opposed to polymyositis that shows Endomysial inflammation (CD8+ T cells) with necrotic muscle fibers

A image thumb
18

Necrosis of muscle fibers is associated with what myositis? Means what type of inflammation is going on?

Polymyositis

Endomysial inflammation (CD8+ T cells) with necrotic muscle fibers

A image thumb
19

If there is upper extremity distal muscle weakness (in the fingers), what myositis are you thinking of?

Inclusion body myositis

- mostly proximal muscle weakness in lower extremities, distal in upper extremities

20

Inclusion body myositis seen primarily in what age/sex?

Older men

21

Which type of inflammatory myopathy doesnt respond to corticosteroids?

Inclusion body myositis

22

Does inclusion body myositis commonly involve organs? If so, which ones?

No, it doesnt

23

PMR stands for what?

Polymyalgia Rheumatica

24

Polymyalgia rheumatica symptoms? 

Pain and stiffness in shoulders and hips, often with fever, malise, and weight loss

25

What is NOT seen in PMR?

Does not cause muscle destruction

26

What lab values are elevated in PMR?

What lab values are normal?

ESR, CRP elevated

CK normal (due to no muscle damage)

27

Polymyalgia Rheumatica is associated with what other disorder?

Temporal (giant cell) arteritis

28

Which is more common: 

Patient with temporal arteritis develops PMR or Patient with PMR develops temporal arteritis?

- 50% of patients with temporal arteritis will develop polymyalgia rheumatic

- only 15% of patients with PMR as primary diagnosis will develop temporal arteritis

29

What are some symptoms of Temporal arteritis?

Systemic symptoms (fever, weight loss, fatigue)

temporal headaches

visual disturbances (can progress to sudden blindness)

jaw or tongue claudication

arthralgies

 tender temporal artery

30

Dreaded complication of temporal arteritis?

Blindness

31

Describe microscopic apperance of giant cell arteritis?

giant cells (not always there), Inflammation of vessel wall, disruption of internal elastic lamina, intimal fibrosis

A image thumb
32

What treatment method is most effect for polymyalgia rheumatica? Distinguishing feature regarding this treatment method.

low dose of corticosteroids. If after 7 days, patient still hasnt responded, bump up dose. If still doesnt respond after another 7 days, rethink diagnosis of PMR

33

What are you looking at here? What is the key feature that gives it away?

Q image thumb

Inclusion body myositis

KEY FEATURE = variation in muscle fiber sizes. 

34

Muscular dystrophy defined as?

Degenerative disorder characterized by muscle wasting and replacement of skeletal muscle by adipose tissue

35

Deletion of dystrophin is associated with what disorder?

X-linked (Duchenne's) Muscular Dystrophy

36

Mutation of dystrophin associated with?

Severity of this disease?

Becker muscular dystrophy. 

Associated with milder form of disease