DM & PM

Dermatomyositis

Dermatomyositis (DM) is an idiopathic inflammatory myopathy (IIM) with characteristic cutaneous findings.


Classification :

1. 1ry idiopathic PM
2. 1ry idiopathic DM ( PM + Skin lesion )
3. PM or DM + Malignancy
4. Juvenile DM
5. PM or DM associated with other CT disorders ( Mixed CT diseases )

Yoy Must search for malignancy especially in old male patients .
"The onset of a rash in patients with pre-existing myositis requires investigation of the neoplastic possibility"

C/p :
1- Muscle :
- bilateral proximal " weakness, wasting but not tender " , facal and distal muscles are not affected .
" DD >> -MG : occular and face affection , increase with use and nocturnal
-Guan Barre : Distal affection > proximal . "
- Dysphagia
- Cardiomyopathy >> HF , arrhythmia

2- Skin :

• Heliotrope rash
• Gottron's sign
• shawl sign ... ?

3- Malignancy
4- Raynaud's phenomenon
5- ISP fibrosis
6- Arthralgia

Investigations :
1- EMG
2- Muscle biopsy , after MRI .. ??
3- CK level
4- ANA
5- Anti-jo-1 .. it is a myositis specific antibody (30%)

Treament :
1- Please search for neoplasms anywhere .
2- Steroids with the usual regimen .
3- Immunosuppressive therapy .
4- Pulse steroid ... ???