Muscle weakness & rash (Dermatomyositis)
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Transcript of Muscle weakness & rash (Dermatomyositis)
MUSCLE WEAKNESS & SKIN RASH( DERMATOMYOSITIS )
Dr. Mohammad Tanvir IslamAssistant Professor , Dept of MedicineBangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh
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
WHAT MAY BE THE CAUSE OF THIS MYOPATHY
Inflammatory myopathy Drug induced Endocrine Infection Alcohol
MYOPATHY WITH SKIN RASH
Dermatomyositis
Steroid induced myopathy
Hypothyroidism
Other CTDs
DERMATOMYOSITIS
Double peak of onset Average age of onset is 40
In 40% individuals the skin disease is the sole manifestation at onset
Muscle disease may occur- Concurrently, Precede the skin disease, or Follow the skin disease by weeks to years.
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
SKIN RASH IN DERMATOMYOSITIS
Heliotrope rash
-violaceous colour-Periorbital edema present
SKIN RASH OF DERMATOMYOSITIS
Gottrone’s papules
Involves the dorsal surface of MCP and IP joints
SKIN RASH OF DERMATOMYOSITIS
Periungual telengiectasia
SKIN RASH OF DERMATOMYOSITIS
Rash in Shawl distribution
COMPLICATIONS
Dermatomyositis & 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
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
CLASSIFICATION CRITERIA FOR POLYMYOSITIS AND 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)
CLINICAL CRITERIA
1975, Bohan and Pete Set of 5 criteria to aid in the diagnosis and
classification of dermatomyositis and polymyositis
1. 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.
SUBSETS OF MYOSITIS
Bohan 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
HOW WILL YOU INVESTIGATE
Enzymes – CK
Aldolase
LDH
carbonic anhydrase isoenzyme III
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
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
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.
Figure 2
Source: The Lancet 2003; 362:971-982 (DOI:10.1016/S0140-6736(03)14368-1)
Terms and Conditions
HISTOPATHOLOGICAL FINDINGS OF DERMATOMYOSITIS & POLY MYOSITIS
A, B: Depletion of capillaries in dermatomyositis (A) with dilatation of the lumen of the remaining capillaries, compared with a normal muscle (B). C: Perifascular atrophy in dermatomyositis. D: Endomysial inflammation in polymyositis and inclusion-body myositis with lymphocytic cells invading healthy fibres. E: The MHC-I/CD8 complex in polymyositis and inclusion-body myositis.
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
TREATMENT
Other drugs used- methotrexate,azathiprine, cyclophosphamide, cyclosporine
IV immunoglobulin for refractory cases
Physiotherapy
TREATMENT
For skin component
Hydroxychloroquine
Topical steroids
sunprotection
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
USEFUL LINKS
http://www.aafp.org/afp/2001/1101/p1565.pdf
http://emedicine.medscape.com/article/332783
The value of experience is not in seeing much, but in seeing wisely.
SIR WILLIAM OSLER
Thank you all