Features:
- progressive proximal muscle weakness
- dysphagia
- interstitial lung disease
- oesophageal dysfunction
- weight loss
- fever
- myocarditis
- arthralgia
To try and remember this list I think of the condition starting in the proximal muscles of the arm then creeping to the joint (causing arthralgia) and onwards to the oesophagus, causing dysphagia and oesphageal dysfunction. I then imagine it seeping into the lungs (interstitial lung disease) and then onwards into the heart (myocarditis).
Skin signs include:
- heliotrope (liliac-purple) rash around eyelids/cheeks
- macular rash over back and shoulders (=shawl sign)
- Gottrons papules = scaly plaques on MCP/PIP joints
- Gottrons sign = erythema over knees/elbows
- periungal telangectasia
- nail fold infarcts
- photosensitivity
There is a higher prevalence of malignancy with dermatomyositis.
Investigations show:
- raised CK/AST/LDH
- abnormal EMG - shows fibrillation potentials
- anti-Jo antibodies associated with a systemic form of disease
Treatment is:
- prednisolone
- methotrexate
- screen for maligancy.
NB: juvenile dermatomyositis is different - it is more aggressive and includes a vasculitis and ectopic calcification.
Now onwards for our first expedition into the world of sexually transmitted diseases...
