Muscle weakness & rash (Dermatomyositis)


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Muscle weakness & rash (Dermatomyositis)

  1. 1. MUSCLE WEAKNESS & SKIN RASH( DERMATOMYOSITIS )Dr. Mohammad Tanvir IslamAssistant Professor , Dept of MedicineBangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh
  2. 2. IS THIS A CASE OF MYOPATHY?? Proximal muscle weakness evident by- Difficulty in standing from sitting position, combing hair etc. Normal tendon reflexes Pain & tenderness often present
  3. 3. WHAT MAY BE THE CAUSE OF THIS MYOPATHY Inflammatory myopathy Drug induced Endocrine Infection Alcohol
  4. 4. MYOPATHY WITH SKIN RASH Dermatomyositis Steroid induced myopathy Hypothyroidism Other CTDs
  5. 5. DERMATOMYOSITIS Double peak of onset Average age of onset is 40 In 40% individuals the skin disease is the sole manifestation at onsetMuscle disease may occur- Concurrently, Precede the skin disease, or Follow the skin disease by weeks to years.
  6. 6. CLINICAL PRESENTATION Proximal myopathy Skin rash Systemic features- fever, malaise , arthralgia, arthritis, dyspnea, dysphagia, arrhythmia, and dysphonia, raynauds. Malignancy- lungs, GI tract, breast, overy etc
  7. 7. Heliotrope rash-violaceous colour-Periorbital edemapresentSKIN RASH IN DERMATOMYOSITIS
  8. 8. Gottrone’s papulesInvolves the dorsal surface of MCP and IP jointsSKIN RASH OF DERMATOMYOSITIS
  9. 9. Periungual telengiectasiaSKIN RASH OF DERMATOMYOSITIS
  10. 10. Rash in Shawl distributionSKIN RASH OF DERMATOMYOSITIS
  11. 11. COMPLICATIONSDermatomyositis & malignancy 6-7 fold increase risk of malignacy Usually early within 3 years of diagnosis chances decreases thereafter Highest in patients diagnosed after 45yrs of age Ovarian and gastric cancer and lymphoma are most common
  12. 12. COMPLICATIONS Cardiomyopathy & Cardiac conduction defects Aspiration pneumonia Diffuse interstitial pneumonitis/fibrosis Large-bowel infarction Muscle atrophy & Muscle calcification Ocular complications including iritis, nystagmus, cotton-wool spots, optic atrophy, conjunctival, edema and pseudopolyposis
  13. 13. CLASSIFICATION CRITERIA FOR POLYMYOSITISAND DERMATOMYOSITIS*1. Skin lesions Heliotrope: red-purple edematous erythema on the upper palpebra Gottron’s sign: red-purple keratotic, atrophic erythema or macules on the extensor surface of finger joints Erythema on the extensor surface of extremity joints, slight raised red-purple erythema over elbows or knees2. Proximal muscle weakness (upper or lower extremity and trunk)3. Elevated serum creatine kinase or aldolase level4. Muscle pain on grasping or spontaneous pain5. Myogenic changes on electromyography (short-duration, polyphasic motor unit potentials with spontaneous fibrillation potentials)6. Positive anti-Jo-1 antibody test (histidyl-tRNA synthetase)7. Nondestructive arthritis or arthralgias8. Systemic inflammatory signs (temperature: more than 37°C [98.6°F] at axilla, elevated serum C-reactive protein level or accelerated erythrocyte sedimentation rate of more than 20 mm per hour by Westergren)9. Pathologic findings compatible with inflammatory myositis (inflammatory infiltration of skeletal evidence of active regeneration may be seen)
  14. 14. CLINICAL CRITERIA 1975, Bohan and Pete Set of 5 criteria to aid in the diagnosis and classification of dermatomyositis and polymyositis1. progressive proximal symmetrical weakness,2. elevated levels of muscle enzymes,3. an abnormal finding on electromyography,4. an abnormal finding on muscle biopsy5. Cutaneous disease.
  15. 15. SUBSETS OF MYOSITISBohan and Peter suggested 5 subsets of myositis, as follows : Dermatomyositis Polymyositis Myositis with malignancy Childhood dermatomyositis/polymyositis Myositis overlapping with another collagen-vascular disorder Others- postmyopathic dermatomyositis amyopathic dermatomyositis [ADM], or dermatomyositis sine myositis
  16. 16. HOW WILL YOU INVESTIGATEEnzymes – CK Aldolase LDH carbonic anhydrase isoenzyme III
  17. 17. ANTIBODIES ANA commonly positive (60-80%) Anti –Mi-2 highly specific but sensitivity only 25% Anti-Jo-1 more in polymyositis,associated with ILD,raynauds and arthritis (positive in 20%) autoantibody against p155 highly associated with cancer
  18. 18. IMAGING MRI- useful in diagnosing inflammatory myopathy(even in patients without weakness), it also helps in taking muscle biopsy in choosing proper site EMG- helps to differentiate from neuropathy and choosing biopsy site. CXR Barium swallow USG CT scan
  19. 19. HISTOPATHOLOGICAL FINDINGS Findings on muscle biopsy can be diagnostic. Perivascular and interfascicular inflammatory infiltrates with adjoining groups of muscle fiber degeneration/regeneration This contrasts with polymyositis infiltrates, which are mainly intrafascicular (endomysial inflammation) with scattered individual muscle fiber necrosis.
  20. 20. Figure 2A, B: Depletion of capillariesin dermatomyositis (A) withdilatation of the lumen of theremaining capillaries,compared with a normalmuscle (B). C: Perifascularatrophy in dermatomyositis.D: Endomysial inflammationin polymyositis and inclusion-body myositis withlymphocytic cells invadinghealthy fibres. E: The MHC-I/CD8 complex in polymyositisand inclusion-body myositis. HISTOPATHOLOGICAL FINDINGS OF DERMATOMYOSITIS & POLY MYOSITIS Source: The Lancet 2003; 362:971-982 (DOI:10.1016/S0140-6736(03)14368-1) Terms and Conditions
  21. 21. TREATMENT Oral prednisolone is the mainstay of treatment 0.5-1.5 mg/kg starting dose.given untill CK level is normal , then tapered slowly over 12 month period Prednisolone itself worsen myopathy in some cases and steroid induced myopathy is differentiated by sparing the neck flexor strength
  22. 22. TREATMENT Other drugs used- methotrexate,azathiprine, cyclophosphamide, cyclosporine IV immunoglobulin for refractory cases Physiotherapy
  23. 23. TREATMENTFor skin component Hydroxychloroquine Topical steroids sunprotection
  24. 24. PROGNOSIS Spontaneous remission in 20% 5% have fulminant progression and eventual death Poor prognostic factor-recalcitrant disease, delay in diagnosis, older age, malignancy, fever, asthenia-anorexia, pulmonary interstitial fibrosis, dysphagia and leukocytosis. Cause of death-Malignancy, cardiac and pulmonary dysfunction, and infection
  25. 25. USEFUL LINKS
  26. 26. The value of experience is not in seeing much, but in seeing wisely. SIR WILLIAM OSLER
  27. 27. Thank you all