Polymyositis- Important Points to remember for PG Exams and USMLE
It is an inflammatory myopathy .Other types of inflammatory myopathies include Dermatomyositis and Inclusion body myositis.
- Symmetrical involvement of Proximal limb muscles and rare involvement of distal limb muscles.
- Involvement of pharangeal muscles can lead to dysphagia
- Neck flexor muscles involvement can lead to head drop and hence difficulty in holding the head.
- Respiratory muscles are involved in advanced stage.
- The most important point is the sparing of Extraocular muscles i.e. these muscles are not involved in inflammatory myopathies.
- There is no involvement of nerves and hence sensations remain normal.
Important point: No involvement of Skin in Polymyositis and no Cardiac involvement
Diagnosis of Polymyositis: Raised level of muscle enzymes, Characteristic EMG findings. However definite diagnosis has to be done by doing Muscle biopsy.
- Corticosteroids are the first line drugs
- Immunosuppressive therapy including Cyclosporine, Azathioprine, mycophenolate mofetil, monoclonal antibody CD 20
- Intravenous immunoglobulins and Rituximab
Other important Topics for NEET PG Exam include: