Dermatomyositis And polymyositis

Question 1

Dermatomyositis and polymyositis

Answer 1

Loss of muscle strength secondary to autoimmune muscle damage

Question 2

Dermatomyositis

Answer 2

Both muscular and cutaneous involvement

Question 3

Polymyositis

Answer 3

No cutaneous involvement

Question 4

Polymyositis pathogenesis

Answer 4

Cellular immunity
CD 8 + cytotoxic Tcells damaging muscles

Question 5

Dermatomyositis pathogenesis

Answer 5

Humoral immunity
Complement activation leading to microangiopathy
Muscle necrosis due to decreased blood supply
CD4+ cells (invading)

Question 6

Skin changes

Answer 6

Periorbital and eyelid edema
Violet tint to eyelids (heliotrope lids)
Reduced facial expression
Raynaud phenomena

Question 7

Changes on finger joints and knucles

Answer 7

Lichenoid papules (Gottron sign)

Question 8

Changes on forehead chin shoulder and upper arm anterior neck and chest (V shape)

Answer 8

Erythematous macules and plaques

Question 9

Finger tip and toe changes

Answer 9

Ulcer and fissures

Question 10

Changes on nail fold

Answer 10

Telangiectasis and atrophy

Question 11

Joint changes

Answer 11

Arthritis

Question 12

Mucosa

Answer 12

Oral ulcers

Question 13

Calcium accumulation

Answer 13

Calcinosis

Question 14

Lungs

Answer 14

Pulmonary fibrosis

Question 15

GIT

Answer 15

Ulcers and hemorrhage

Question 16

Heart

Answer 16

Myocarditis

Question 17

Diagnosis

Answer 17

EMG
MRI
Muscle biopsy
Polymyositis CD8
Dermatomyositis CD4
Serology: myositis specific antibodies

Question 18

Therapy

Answer 18

Corticosteroids