II. Epidemiology
- Twice as common in women
- Mean age at diagnosis
- Adults: 40 years
- Children: 4 to 14 years, peaking at ages 4-10 years (juvenile Dermatomyositis)
III. Pathophysiology
- Group 2 of Polymyositis disorders (accounts for 25%)
- Classification
- Without Muscle Weakness (amyopathic Dermatomyositis)
- With Muscle Weakness
- Pediatric Dermatomyositis
- Adult Dermatomyositis (with or without cancer)
IV. Signs: Pathognomonic for Dermatomyositis
- Gottron's Papules (33% to 70% of patients)
- Gottron's Sign
V. Signs: Characteristic Findings
- Facial photosensitivity and dusky erythema on face
- Classic lilac-colored (heliotrope) rash
- Occurs in 30 to 60% of patients early in disease
- Distribution
- Eyelids and periorbital area
- Bridge of nose
- Malar area
- Erythematous, poikilodermatous Macules
- V-area of neck (V-sign)
- Shoulders and upper back (Shawl sign)
- Periungual Vasculitis
- Vertical Telangiectases involve cuticles
- Mechanic's hand
- Fissured, scaly, hyperkeratotic, hyperpigmented hands
VI. Signs: Other Findings
- Poikiloderma atrophicans vasculare
- Circumscribed violaceous erythema
- Occurs late in Dermatomyositis
- Associated findings
- Central atrophy
- Telangiectasia
- Hypopigmentation
- Distribution
- Posterior Shoulders, back and buttocks
- V-shaped area of anterior neck and chest
- Calcinosis cutis
VII. Associated Systemic Signs and Conditions
- See Polymyositis
- Proximal Muscle Weakness
- Gowers' Sign
- Uses arms to raise self
- Trendelenburg's Sign
- Weakness of raised leg in one legged standing
- Gowers' Sign
- Common Systemic Associations
- Less common systemic associations
- Respiratory Muscle Weakness
- Visual changes
- Abdominal Pain
- Malignancy (only seen in adult Dermatomyositis)
- Highest risk over age 45 years
- Most commonly associated cancers
- Less commonly associated cancers
- Lung Cancer
- Cancer of male genitalia
- Skin Cancer (Melanoma and non-Melanoma)
- Kaposi's Sarcoma
- Mycosis Fungoides
VIII. Subtypes
- Juvenile Dermatomyositis findings
- Low-grade fever
- High fever with rash and profound Muscle Weakness in acute onset (25% of cases)
- Gastrointestinal symptoms
- Symmetric Arthritis of large and small joints
- Cardiac conduction delay
- Truncal and proximal Muscle Weakness (may use Gower's Sign)
- No malignancy association
- Low-grade fever
- Overlap Syndrome (comorbid Connective Tissue Disease)
- Amyopathic Dermatomyositis (2-11%)
- Pathognomonic skin changes without Myositis
- Presenting symptoms
- Lethargy or Fatigue
- Pruritus
- Photosensitivity
- Arthralgias
IX. Differential Diagnosis
X. Radiology
XI. Labs: Initial Evaluation
-
Myositis Labs
- Alanine Aminotransferase (ALT)
- Aspartate Aminotransferase (AST)
- Lactate Dehydrogenase (LDH)
- Creatine Phosphokinase (CPK)
- Aldolase (consider)
- Urinalysis for creatinuria or Myoglobinuria
- Sedimentation rate (ESR) elevated
- Complete Blood Count (CBC) identifies Anemia
- Antinuclear Antibody (ANA)
- Serum chemistry panel
- Stool Guaiac
XII. Labs: Secondary Evaluation
- See Dermatomyositis Evaluation
- Electromyogram (EMG) shows myopathic pattern
- Consider biopsy
- Muscle biopsy
- Skin biopsy (to rule-out other causes)
XIII. Management
Images: Related links to external sites (from Bing)
Related Studies
| Definition (CHV) | an inflammatory muscle disease accompanied by muscle weakness and skin rash |
| Definition (CHV) | an inflammatory muscle disease accompanied by muscle weakness and skin rash |
| Definition (CHV) | an inflammatory muscle disease accompanied by muscle weakness and skin rash |
| Definition (MSH) | A subacute or chronic inflammatory disease of muscle and skin, marked by proximal muscle weakness and a characteristic skin rash. The illness occurs with approximately equal frequency in children and adults. The skin lesions usually take the form of a purplish rash (or less often an exfoliative dermatitis) involving the nose, cheeks, forehead, upper trunk, and arms. The disease is associated with a complement mediated intramuscular microangiopathy, leading to loss of capillaries, muscle ischemia, muscle-fiber necrosis, and perifascicular atrophy. The childhood form of this disease tends to evolve into a systemic vasculitis. Dermatomyositis may occur in association with malignant neoplasms. (From Adams et al., Principles of Neurology, 6th ed, pp1405-6) |
| Definition (CSP) | progressive condition characterized by symmetric proximal muscular weakness with elevated serum levels of muscle enzymes and a skin rash, typically a purplish-red erythema on the face, and edema of the eyelids and periorbital tissue; affected muscle tissue shows degeneration of fibers with a chronic inflammatory reaction; occurs in children and adults, and in the latter may be associated with visceral cancer or other disorders of connective tissue. |
| Concepts | Disease or Syndrome (T047) |
| MSH | D003882 |
| ICD9 | 710.3 |
| ICD10 | M33 , M33.9, M33.90 |
| SnomedCT | 203795006, 38826005, 156456005, 201448000, 201445002, 396230008 |
| English | Dermatomyositides, Dermatomyositis, Dermatopolymyositis, Dermatopolymyositis, unspec, Dermatopolymyositis, unspecified, POLYMYOSITIS/DERMATOMYOSITIS, [X]Dermatopolymyositis, unspec, [X]Dermatopolymyositis, unspecified, POLYMYOSITIS DERMATOMYOSITIS, Polymyositis Dermatomyositis, Polymyositis-Dermatomyositides, Polymyositis-Dermatomyositis, Dermatopolymyositides, Dermatopolymyositis, unspecified, organ involvement unspecified, Dermatomyositis [Disease/Finding], dermatomyositis, dermatomyositides, Dermatopolymyositis, unsp, organ involvement unspecified, dermatopolymyositis (diagnosis), [X]Dermatopolymyositis, unspecified (disorder), DERMATOMYOSITIS, Wagner-Unverricht syndrome, Polymyositis with skin involvement, DM - Dermatomyositis, Dermatomyositis (disorder), dermatopolymyositis, polymyositis; with involvement of skin, dermatomucosomyositis |
| French | DERMATOMYOSITE, Dermatomyosite, Polymyosite-Dermatomyosite |
| Portuguese | DERMATOMIOSITE, Dermatomiosite, Polimiosite-Dermatomiosite |
| Spanish | DERMATOMIOSITIS, síndrome de Wagner - Unverricht, polimiositis con compromiso de piel, [X]dermatopolimiositis, no especificada, [X]dermatopolimiositis, no especificada (trastorno), dermatomiositis (trastorno), dermatomiositis, Dermatomiositis, Polimiositis-Dermatomiositis |
| German | DERMATOMYOSITIS, Dermatomyositis-Polymyositis, nicht naeher bezeichnet, Dermatomyositis-Polymyositis, Dermatomyositis, Polymyositis-Dermatomyositis, Dermatopolymyositis |
| Swedish | Dermatomyosit |
| Japanese | ﾋﾌｷﾝｴﾝ, 筋炎-皮膚, 皮膚筋炎 |
| Czech | dermatomyozitida, Dermatomyozitida, polymyozitida - dermatomyozitida, dermatopolymyozitida |
| Finnish | Dermatomyosiitti |
| Russian | DERMATOMIOZIT, POLIMIOZIT-DERMATOMIOZIT, ДЕРМАТОМИОЗИТ, ПОЛИМИОЗИТ-ДЕРМАТОМИОЗИТ |
| Italian | Polimiosite-dermatomiosite, Dermatopolimiosite, Dermatomiosite |
| Korean | 상세불명의 피부다발성근육염, 피부다발근육염 |
| Croatian | DERMATOMIOZITIS |
| Polish | Zapalenie skórno-mięśniowe |
| Hungarian | Dermatomyositis |
| Norwegian | Dermatomyositt |
| Dutch | polymyositis; met huidaandoening, Dermatopolymyositis, niet gespecificeerd, dermatomyositis, Dermatomyositis, Dermatopolymyositis, Polymyositis-dermatomyositis |
Ontology: Gottron's papules (C0423781)
| Concepts | Finding (T033) |
| ICD10 | L94.4 |
| SnomedCT | 247455006, 201084000 |
| Dutch | Gottron-papellen, Gottron; papel, papel; Gottron, Papula van Gottron |
| French | Papules de Gottron |
| German | Gottron-Papeln |
| Italian | Papule di Gottron |
| Portuguese | Pápulas de Gottron |
| Spanish | Pápulas de Gottron, pápulas de Gottron (hallazgo), pápulas de Gottron |
| Japanese | ゴットロン丘疹, ｺﾞｯﾄﾛﾝｷｭｳｼﾝ |
| Czech | Gottronovy papuly |
| Korean | 고트론 구진 |
| English | Gottron papules, gottron's papules, gottron's papule, gottron's papules (diagnosis), Gottron's papules (disorder), Gottron's papules, Gottron's papules (finding), Gottron; papule, papule; Gottron |
| Hungarian | Gottron-papulák |
Ontology: Idiopathic dermatomyositis (C0554592)
| Concepts | Disease or Syndrome (T047) |
| SnomedCT | 281358000 |
| English | Idiopathic dermatomyositis, Idiopathic dermatomyositis (disorder) |
| Spanish | dermatomiositis idiopática (trastorno), dermatomiositis idiopática |
