Dermatomyositis Flashcards
Forms of dermatomyositis
- Classic dermatomyositis (autoimmune disease affecting both muscle and skin)
- Amyopathic dermatomyositis (autoimmune disease affecting just skin)
Muscle involvement in dermatomyositis
- Symmetric weakness in proximal limb muscles
Complications of dermatomyositis
- Malignancy
- Systemic involvement (esp. lungs)
- Diaphragm atrophy
- Calcinosis cutis (calcium deposits in skin)
Classic presentation for dermatomyositis
- Skin-wide poikiloderma and pink-violaceous rash often with heliotropic distribution (periocular) and scalp distribution
- Rashes worsen substantially with sunlight, and esp. prominent in neck area due to sun exposure (V-neck sign, shawl sign)
- Muscle weakness in brachium and thigh
- High creatine kinase levels (from muscle degradation)
- Streaks of red in nailfolds
- Flares triggered by stress
- Grotton’s papules in MCPs, PIPs, and/pr DIPs
Patients with dermatomyositis often first present to clinic with chronic mild symptoms that are acutely worsening during ____
Patients with dermatomyositis often first present to clinic with chronic mild symptoms that are acutely worsening during a period of social stress
Poikiloderma
- Pink-violet rash consisting of areas of hyperpigmentation, hypopigmentation, telangiectasis (widening of blood vessels), and atrophy
Onset of dermatomyositis is associated with . . .
. . . an external trigger that interacts with the immune system. Usually a drug or infection.
Emerging evidence implicates ___ as the source of pathology in dermatomyositis. This also implicates ___ as the source of ___.
Emerging evidence implicates IFNβ as the source of pathology in dermatomyositis. This also implicates plasmacytoid dendritic cells (pDCs) as the source of IFNβ.
Pathognomonic features of dermatomyositis
- Heliotrope eruption
- Grotton’s papules
Grotton’s papules are often confused for. . .
. . . psoriasis
Cutis cacinosis is often confused for. . .
. . . tophi
Grotton’s papules
Heliotrope sign
Heliotrope sign
Lab findings of dermatomyositis
- Elevated creatine kinase
- Elevated lactate dehydrogenase
- Elevated aldolase
- Elevated liver enzymes (ALT AST)
- Imaging studies of muscle to establish atrophy (EMG, MRI, biopsy)
Systemic symptoms of dermatomyositis
- Interstitial lung disease (15-30%, antisynthetase syndrome)
- Liver disease
- Muscle degradation
- Increased risk of malignancy
- Fever
Antisynthetase syndrome
- Associated with antisynthetase autoantibodies, esp. Jo-1
- Fever
- Erosive polyarthritis
- “Mechanic’s hands” -> hyperkeratosis, fissuring of lateral and palmar aspects of hand
- Reynaud’s phenomenon
- Interstitial lung disease (70% of patients with anti-Jo-1 go on to develop)
When dermatomyositis and a malignancy are diagnosed in a close time fashion, the dermatomyositis may be thought of as ____
When dermatomyositis and a malignancy are diagnosed in a close time fashion, the dermatomyositis may be thought of as a paraneoplastic phenomenon
Treatment for dermatomyositis
- Corticosteroids
- Methotrexate
- IVIG
