What is the difference between polymyositis and dermatomyositis?

Symptom differences: polymyositis will cause proximal muscle weakness and myalgia; In addition to the above-mentioned muscle symptoms, dermatomyositis can also present with specific rashes, such as sunny rashes and shawl rashes;

Pathological differences: dermatomyositis is mainly vasculitis, and polymyositis is mainly hormonal inflammation.

The typical clinical manifestations of polymyositis are symmetrical proximal muscle weakness and muscle tenderness, while dermatomyositis has a variety of rashes in addition to the above clinical manifestations.

This is an open classification on polymyositis and dermatomyositis, with a total of 7 entries (including subclasses).

Polymyositis (PM) and dermatomyositis (DM) are non-purulent, autoimmune inflammatory diseases of striated muscle. The main pathological features are necrosis and regeneration of muscle fiber Hobwe, and infiltration of inflammatory cells in the interstitial muscle. Polymyositis refers to myositis without ** damage, while myositis with rash is called dermatomyositis.

The exact cause of polymyositis dermatomyositis is unknown, but genetic, immunological, tumor, and infections with a variety of pathogens, including bacteria, viruses, fungi, and parasites, may be involved.

Polymyositis dermatomyositis is still a diagnosis of exclusion, and all inflammatory myopathies that cannot find clear infectious agents (viruses, bacteria, parasites, etc.) belong to this disease, so they are also called idiopathic inflammatory myopathy. Because this group of diseases responds well to corticosteroids**, it is speculated that the pathogenesis may be related to autoimmune abnormalities. It can occur at any age.

It is more common in females than males, and the male-to-female ratio is about 1:2.

The main clinical manifestation of polymyositis (PM) is diffuse inflammatory myopathy with weakness and pain in the proximal limbs, neck, and pharynx. If the rash is present, it is called dermatomyositis (DM). About 1 3 patients may have other connective tissue diseases, and 1 10 patients may have tumors.

Polymyositis, dermatomyositis, renal impairment is seen in a small number of patients.

The incidence of dermatomyositis and polymyositis is still not well understood, and it is thought that the onset may be related to viral infections, immune abnormalities, genetics, and tumors.

First, the main **.

1. Autoimmune system: immune system disorders are the basis for the onset and progression of dermatomyositis and polymyositis, and T cells are the main inflammatory cells in polymyositis and dermatomyositis.

2. Genetic factors: Genomic studies have shown that IFN-ɑ and IFN- gene signals are highly expressed in the muscle tissues of patients with dermatomyositis, and type I IFN signals are more obvious in dermatomyositis.

2. Predisposing factors.

The onset of the disease is mostly insidious, and it is difficult for most patients to say the exact time of onset, and most patients present for muscle weakness.

Psychiatric disorders associated with polymyositis and dermatomyositis are connective tissue disorders of unknown cause. At present, it is considered to be an autoimmune disease, and in recent years, it has been believed that cellular immunity deficiency has important pathogenic significance, some people believe that the disease is closely related to malignant tumors, and it has also been reported that 50% of dermatomyositis patients over 40 years old have cancer. Vascular injury may be causative.

It can be induced by infection, sun exposure, drugs, and other factors. Polymyositis is the main factor in the onset of mental disorders, which lead to brain dysfunction secondary to physical diseases. However, only a small number of patients with polymyositis develop mental disorders, so polymyositis is not the only one associated with mental disorders**, and there are other factors related to the occurrence of mental disorders, such as other biological factors, including the patient's gender, age, genetic factors, personality characteristics, and previous history of neuropsychiatric disorders. Psychological factors include stress state, long-term psychological conflict, etc.; Environmental factors such as crowded living, noisy, humid environment, air pollution, etc.

All of the above factors can be precipitating factors for polymyositis and psychiatric disorders.

The main clinical manifestations of polymyositis are diffuse muscle inflammatory diseases characterized by symmetrical weakness of proximal limbs, cervical muscles, and pharyngeal muscles, muscle tenderness, and increased serum enzymes. Most scholars believe that the disease is related to an autoimmune disorder. Some scholars believe that it is related to viral infection or genetic factors.

Most of them have a subacute onset, and can occur at any age, more common in middle-aged people and above, and slightly more in women. Some patients have malignant tumors before the disease, and about 20 patients have other diseases such as lupus erythematosus, scleroderma, rheumatoid arthritis, and Sjögren's syndrome. Due to the different scope of involvement, the clinical manifestations of the disease are diverse.

The disease usually peaks within a few weeks to months, with generalized muscle weakness and, in severe cases, respiratory muscle weakness, which is life-threatening. Therefore, early diagnosis and ** are very important. As long as corticosteroids or immunosuppressants** are used promptly, the prognosis of polymyositis alone is expected to be good, and the prognosis of patients with malignant tumors and various connective tissue diseases is poor.

It is not rheumatism and is an autoimmune disease.

Onset is muscle weakness, muscle tenderness, and in severe cases, dyspnea.

Adrenocorticosteroids can be used**, patients should rest more, exercise slowly in moderation, maintain a happy spirit, and strengthen their confidence in overcoming the disease. Usually avoid receiving strong light, eat less photosensitive foods such as celery, shiitake mushrooms, etc., and eat more yams, wolfberries, angelica, and Ganoderma lucidum.