Polymyositis (PM): Inflammatory autoimmune disease of the musculature with symmetrically occurring muscle inflammations, primarily affects the thigh and upper arm muscles.
Dermatomyositis (DM): Polymyositis with involvement of the skin in light-exposed areas of the body.
Both diseases occur preferentially between the ages of 45 and 60 and affect 70% of women. The course of the disease varies, but it usually progresses slowly and episodically. About half of the patients can be cured by cortisone therapy over several years.
Leading symptoms
– Muscle aches and pains – Fatigue, exhaustion, fever, weight loss – Difficulties getting up, sitting down and climbing stairs – Problems lifting arms, combing, brushing teeth – Difficulties swallowing.
In dermatomyositis additionally:
– Swelling of the upper eyelids, tearful facial expression – Scaling, inflammatory skin redness, typically of a purplish color, on the face or neckline – Scaling skin redness over the extensor sides of the base and middle joints of the fingers, on the elbows, knees and ankles – Skin hardening, pigmentation disorders and mucosal inflammation.
The disease
33-year-old male dermatomyositis patient with typical skin redness v. a. around the eyes. Sometimes the reddish-blue skin changes are also accompanied by edema around the eyes. In both diseases, inflammation occurs over a large area. Then to the decay of muscle fibers. The cause of these autoimmune diseases is unknown. A genetic predisposition and various viruses are being discussed. In 20% of affected individuals, a completely different mechanism, namely cancer (as paraneoplastic symptoms) triggers the disease. If it can be completely removed, the myositis also disappears. In case of symmetrical weakness of the shoulder-. pelvic muscles, an experienced doctor immediately thinks of the correct diagnosis. If laboratory tests reveal typical findings of muscle inflammation (elevated CK), the suspicion is confirmed. Sometimes EMG (electromyography) or a biopsy to confirm the diagnosis. In any case, the doctor must look for a malignant tumor.
The disease usually responds well to treatment with cortisone (z. B. Prednisolone ) to. If the symptoms improve, the dose of cortisone is gradually reduced while monitoring the laboratory values. However, even with optimal therapy, the symptoms recede only slowly.
For severe clinical symptoms, a basic therapeutic agent such as azathioprine is recommended . High-dose immunoglobulins (IVIG) are also effective. Damage to the musculature can be alleviated by regular physiotherapy.