Dermatomyositis
Overview
- Etiopathogenesis: UV light, viruses or medications trigger autoantibodies (e.g., Anti-Mi2, Anti-TIF1γ) in genetically predisposed individuals. Pathomechanism: Antibody binding to endothelial cells & complement activation. This leads to capillary permeability and infiltration of muscle/skin.
- Cutaneous Manifestations: Heliotrope rash (periorbital), Gottron's papules (extensor surfaces of fingers), Shawl sign (V-neck area), Mechanic's hands, Keinig's sign (nailfold megacapillaries), and Holster sign (thighs).
- Systemic Manifestations: Muscle weakness with preserved sensation & intact deep tendon reflexes. Organs: Heart (DCM, pericarditis), Lungs (NSIP, COP). Mortality due to malignancies or pulmonary complications.
- Specific Autoantibodies & Association: Anti-TIF1γ & Anti-NXP2 (Paraneoplasia risk).
Differential diagnoses
- Lupus erythematosus gesicht
- Rosacea
- Bloom syndrome
- Xeroderma pigmentosum (XP)
- Ataxia telangiectasia
- Limited systemic sclerosis (CREST syndrome)
- Urticaria
- Seborrhoeic dermatitis
Practise Dermatomyositis in the app
Flashcards with spaced repetition, exam questions and spot-the-diagnosis on this topic – in DermaFuchs, free of charge.
In the DermaFuchs app: 6 flashcards · 7 clinical images
Open in browser Download on the App StoreSources (selection)
More connective tissue diseases
Note: This page is intended for medical education and does not replace diagnosis or treatment decisions in individual cases. Treatment and follow-up content is available in the app.