Idiopathic Inflammatory Myopathies

Question 1

Dermatomyositis

Answer 1

• gottron papules-scaly, purplish papules and plaques over metacarpal and interphalangeal joints
• heliotrope rash-edematous lilac discoloration of peri orbital tissue

Question 2

Findings in both polymyositis and dermatomyositis

Answer 2

• Gradual onset of painless proximal muscle, pharyngeal,and resp muscle weakness
• mechanics hands: scaly, rough, dry, cracked horizontal lines on the Palmar and lateral aspects of the fingers

Question 3

Diagnostic tests

Answer 3

Serum CK
Emg
Muscle biopsy is gold standard

Question 4

Inclusion body myositis

Answer 4

Insidious and involves proximal and distal muscles
Asymmetric distribution
Quadriceps, wrist, finger flexor muscle weakness is common
ANA positive in

Question 5

Mimics of polymyositis

Answer 5

Muscle fasciculations-ALS
Oculomotor weakness with ptosis-myasthenia gravis
Proximal muscle tenderness-polymyalgia rheumatica
Muscle atrophy, hyporeflexia-peripheral neuropathy
Goiter, delayed reflexes, weight gain-hypothyroid
Treatment with statin-statin myopathy

Question 6

Treatment of inflammatory myopathies

Answer 6

Polymyositis and dermatomyositis:
-first line is high dose steroids
-add MTx or azathioprine if refractory to steroids
-IV immunoglobulin for refractory disease
Cutaneous dermatomyositis:
-hydroxychloroquine

Question 7

Major types of myopathies

Answer 7

Polymyositis
Dermatomyositis
Inclusion body myositis