Dermatomyositis

2024 Author: Rachel Wainwright | [email protected]. Last modified: 2023-12-15 07:39

The content of the article:

Causes and risk factors
Forms of the disease
Disease stages
Symptoms
Features of the course of dermatomyositis in children
Diagnostics
Treatment
Possible complications and consequences
Forecast
Prevention

Dermatomyositis (generalized fibromyositis, generalized myositis, angiomyositis, sclerodermatomyositis, poikilodermatomyositis, polymyositis) is a systemic inflammatory disease that affects muscle tissue, skin, capillaries and internal organs.

Cutaneous manifestations of dermatomyositis

Causes and risk factors

The main role in the pathological mechanism of dermatomyositis development belongs to autoimmune processes, which can be considered as a failure of the immune system. Under the influence of provoking factors, it begins to perceive smooth and transversely hairy muscle fibers as foreign and to develop antibodies (autoantibodies) against them. They not only damage the muscles, but are also deposited in the blood vessels.

The main reason for the development of dermatomyositis is a failure of the immune system

It is suggested that the development of dermatomyositis may be due to neuroendocrine factors. This is partly confirmed by the development of the disease in the transitional periods of life (during puberty, menopause).

Predisposing factors:

some viral infections (Coxsackie virus, picornaviruses);
malignant neoplasms;
hypothermia;
hyperinsolation (prolonged exposure to the sun);
stress;
allergic reactions;
hyperthermia;
pregnancy;
drug provocations, including vaccination.

Forms of the disease

Depending on the cause of the occurrence, the following forms of dermatomyositis are distinguished:

idiopathic (primary) - the disease begins by itself, without connection with any factors, it is not possible to find out the cause;
secondary tumor (paraneoplastic) - develops against the background of malignant tumors;
children (juvenile);
combined with other pathologies of the connective tissue.

By the nature of the inflammatory process, dermatomyositis is acute, subacute and chronic.

Disease stages

In the clinical picture of dermatomyositis, several stages are distinguished:

Prodromal period - nonspecific precursors of the disease appear.
Manifest period - characterized by a detailed clinical picture with vivid symptoms.
The terminal period is characterized by the development of complications [for example, dystrophy, exhaustion (cachexia)].

Symptoms

One of the earliest non-specific signs of dermatomyositis is muscle weakness in the lower extremities, which gradually increases over time. Also, the manifest period of the disease may be preceded by Raynaud's syndrome, polyarthralgia, and skin rashes.

Weak muscles of the lower extremities - a non-specific sign of dermatomyositis

The main symptom of dermatomyositis is the defeat of the skeletal (striated) muscles. Clinically, this is manifested by the growing weakness of the muscles of the neck and upper limbs, which over time makes it difficult to perform the most common, routine actions. In severe cases of the disease, due to severe muscle weakness, patients lose the ability to move and self-care. As dermatomyositis progresses, the muscles of the pharynx, upper digestive tract, diaphragm, and intercostal muscles are drawn into the pathological process. The result is:

disorders of speech function;
dysphagia;
impaired ventilation of the lungs;
recurrent congestive pneumonia.

Dermatomyositis is characterized by skin manifestations:

erythematous spotted rash;
periorbital edema;
Gottron's symptom (periungual erythema, striation of the nail plate, redness of the palms, erythematous scaly spots on the skin of the fingers);
alternation of areas of skin atrophy and hypertrophy, pigmentation and depigmentation.

The defeat of the mucous membranes against the background of dermatomyositis leads to the development of:

hyperemia and swelling of the pharyngeal walls;
stomatitis;
conjunctivitis.

The defeat of the mucous membranes with dermatomyositis leads to the development of conjunctivitis

Systemic manifestations of dermatomyositis include lesions:

joints (phalangeal, wrist, elbow, shoulder, ankle, knee);
hearts - pericarditis, myocarditis, myocardiofibrosis;
lungs - pneumosclerosis, fibrosing alveolitis, interstitial pneumonia;
organs of the gastrointestinal tract - hepatomegaly, dysphagia;
nervous system - polyneuritis;
kidney - glomerulonephritis with impaired renal excretory function;
endocrine glands - a decrease in the function of the gonads and adrenal glands.

Features of the course of dermatomyositis in children

Compared with adult patients, dermatomyositis in children begins more acutely. The prodromal period is characterized by:

general malaise;
increased body temperature;
myalgia;
decreased muscle strength;
arthralgia;
general weakness.

The clinical picture of juvenile dermatomyositis combines signs of damage to various organs and systems, but the most pronounced inflammatory changes on the part of the skin and muscles.

In children and adolescents, against the background of dermatomyositis, intramuscular, intrafascial and intradermal calcifications can form, usually localized in the projection of large joints, buttocks, shoulder girdle and pelvis.

Diagnostics

The main diagnostic criteria for dermatomyositis:

clinical symptoms of damage to the muscular system and skin;
characteristic pathomorphological changes in muscle fibers;
electromyographic changes;
increased activity of serum enzymes.

The auxiliary (additional) diagnostic markers of dermatomyositis include calcification and dysphagia.

Immunological analysis detects antibodies to myosin, endothelium, thyroglobulin

Dermatomyositis is diagnosed when:

skin rash, combined with any three main criteria;
skin manifestations, two main and two additional criteria.

To confirm the diagnosis, a laboratory and instrumental examination is carried out:

a general blood test (an increase in ESR, leukocytosis with a shift in the leukocyte formula to the left is detected);
biochemical blood test (for an increase in the level of aldolase, transaminases, seromucoid, haptoglobin, sialic acids, myoglobin, fibrinogen, α2- and γ-globulins);
immunological blood test (reveals the presence of nonspecific antibodies to the endothelium, myosin, thyroglobulin, an increase in the level of myositis-specific antibodies, a small amount of antibodies to DNA and LE-cells, a decrease in the level of IgA with a simultaneous increase in IgM and IgG, a decrease in the number of T-lymphocytes, a decrease in titer complement);
histological examination of a musculocutaneous biopsy (loss of cross striation, inflammatory infiltration of myocytes, degenerative changes, pronounced fibrosis are established);
electromyography (fibrillar vibrations at rest, polyphasic short-wave changes, increased muscle excitability are detected).

Treatment

Dermatomyositis therapy is aimed at suppressing the activity of the autoimmune inflammatory process and is usually carried out with long-term corticosteroids (1-2 years). If necessary, non-steroidal anti-inflammatory drugs, in particular salicylates, can be included in the scheme.

If corticosteroid therapy is ineffective, cytostatics are prescribed with a pronounced immunosuppressive effect.

Long-term corticosteroids are indicated for the treatment of dermatomyositis.

To improve the contractile function of muscles, injections of Proserin, B vitamins, cocarboxylase, and ATP are used.

In recent years, plasmapheresis and lymphocytapheresis have been used in the complex treatment of dermatomyositis.

To prevent the formation of muscle contractures, regular exercise therapy is shown.

Possible complications and consequences

In the absence of adequate therapy, dermatomyositis slowly progresses, leading to severe muscle weakness, damage to internal organs. This becomes the cause of patient disability, and in severe cases, death.

Long-term corticosteroid therapy for dermatomyositis can cause a number of pathologies:

arterial hypertension;
obesity;
osteoporosis;
diabetes.

Forecast

In the absence of adequate treatment, about 40% of patients die in the first two years from the moment of diagnosis; the cause is gastrointestinal bleeding and respiratory failure.

Immunosuppressive therapy significantly improves long-term prognosis. However, even against its background, persistent joint contractures are formed in some patients, and deformation of the upper and lower extremities occurs.

Prevention

Primary measures for the prevention of dermatomyositis have not been developed. Secondary prevention is aimed at preventing exacerbations of the disease and reducing the activity of the inflammatory process. It includes:

sanitation of foci of chronic infection;
limiting physical activity;
avoidance of excessive insolation and hypothermia;
compliance with the daily routine;
dispensary control of a rheumatologist;
careful adherence to the drug therapy regimen prescribed by the doctor.

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Elena Minkina Doctor anesthesiologist-resuscitator About the author

Education: graduated from the Tashkent State Medical Institute, specializing in general medicine in 1991. Repeatedly passed refresher courses.

Work experience: anesthesiologist-resuscitator of the city maternity complex, resuscitator of the hemodialysis department.

The information is generalized and provided for informational purposes only. At the first sign of illness, see your doctor. Self-medication is hazardous to health!