Polymyositis and dermomyositis

Question 1

What characterises polymyositis and dermatomyositis? (4)

Answer 1

Insidious onset of progressive symmetrical proximal muscle weakness
Autoimmune-mediated striated muscle inflammation
Myalgia
+- arthralgia

Question 2

What other symptoms can muscle weakness cause? (3)

Answer 2

Dysphonia (not dysphasia)
Dysphagia
Respiratory weakness

Question 3

What features does dermatomyositis also include?

Answer 3

Macular rash
Lilac-purple rash on eyelids +- oedema
Nail fold erythema
Gottrons papules (roughened red papules over knuckles, elbows and knees)
Subcutaneous calcification

Question 4

What are the extra muscular features of polymyositis and dermatomyositis?

Answer 4

Fever
Arthralgia
Raynauds
Interstitial lung fibrosis
Myocardial involvement (Arrhythmias, myocarditis)

Question 5

What is the management of polymyositis and dermatomyositis?

Answer 5

Prednisolone 1mg/kg/d PO
Immunosuppressives/cytokines used early in resistant cases
Hydroxychloriquine may help with skin disease