炎性肌病和系统性血管炎

6
DIAGNOSIS
Bohan and Peter Criteria for Polymyositis and Dermatomyositis, 1975
PM确诊：符合所有1~4条； DM确诊：第5条及1~4条中任3条。
DM
皮疹
1. 发病机制不同 2. 病理不同
2020/10/20
PM
周围血 肌细胞和肌内膜 肌束膜和血管周围区
Gastrointestinal Tract
Difficulty swallowing Reflux, weakness in the lower esophagus
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4 PHYSICAL EXAMINATION
Muscle strength
The skin should also be examined to detect changes including those in nail folds and the scalp. Joints can be affected by arthritis, heart and lung changes should be carefully looked for.
histopathologically by the presence of inflammatory cells in muscle tissue
separate IIM subtypes:
Polymyositis (PM) Dermatomyositis (DM) Juvenile DM Necrotizing myopathy (IMNM) Sporadic inclusion body myositis (sIBM)
IBM
in individuals older than 50 years;
rare in younger adults
3 CLINICAL FEATURES
Muscle weakness
slow onset of muscle fatigue, pain and atrophy progressive weakness of proximal limb muscles
PM usually in the late teens or older;
the mean age at onset being 40 to 60 years;
F:M ratio > 2:1)
DM
two peaks— 5 to 15 years 45 to 65 years
F:M ratio > 2:1)
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Lung
Dyspnea and cough are common. weakness of the respiratory muscles
inflammation of the lung tissue (interstitial lung disease)
Lung involvement is frequent in PM and DM and is a major risk factor for mortality.
Joint pain and arthritis are common arthritis is typically nonerosive
Most frequently, arthritis is seen in patients with anti–Jo-1 Ab and other antisynthetase Abs.
1
Definition
The idiopathic inflammatory myopathies (IIMs) are a group of rare, systemic autoimmune diseases characterized
clinically by progressive proximal muscle weakness
Heart
Cardiac involvement may be overlooked conduction abnormalities and arrhythmias Myocarditis, result in sudden death
CK-MB/total CK ratio may be greater than 3% increased serum levels of cardiac isoform troponin I
插入电位：肌病急性期或活动期插入电位活动性增强，慢性期减弱 纤颤电位和正锐波：异常的自发放电 自发奇异高频放电：提示炎性肌病 低波幅，短时限，多相运动单位电位
Imaging
the symmetric inflammation in the affected muscle
多为对称性病变。T1等信号，T2高信号，提示肌肉炎性水肿部位。
5
Skin symptoms
Gottron’ s signs
V-sign
Heliotrope rash Shawl sign
Periorbital oedema
Mechanic’s hand
Raynaud ’ s phenomenon
Calcinosis cutis
Ulceration
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Arthritis
5 LABORATORY EVALUATION
Biochemical
Measuring serum levels of muscle enzymes
Immunologic
ANAs are found in approximately 60% to 70% of myositis patients.
Myositis-specific autoantibodies
Myositis – associated autoantibodies
Anti- RNP Anti- SSA Anti- SSB
2020/10/20
Electromyography 鉴别是肌源性的？还是神经源性的？
Electromyogram (EMG) changes are usually nonspecific but are a useful indicator of myopathic changes.