Some of these additional tests may include a WBC differential, a blood smear review, or in severe conditions, a bone marrow examination. A differential may indicate which type of WBC is low or high while a blood smear and/or bone marrow biopsy can reveal the presence of abnormal and/or immature WBCs. ^ Back to top.
The most common types are dermatomyositis, polymyositis, necrotising autoimmune myopathy and sporadic inclusion body myositis (IBM). Although dermatomyositis affects the skin and muscles, it may also affect other parts of the body such as joints, oesophagus, lungs and heart.
Polymyositis (PM) is an inflammatory disorder in which muscle tissue becomes inflamed and deteriorates, causing weakness and pain. It is one of several types of inflammatory muscle disease, or myopathy. Others include dermatomyositis (DM) and inclusion body myositis.