Juvenile dermatomyositis

Juvenile dermatomyositis (juvenile idiopathic dermatomyositis, juvenile dermatomyositis) is a severe progressive systemic disease with predominant damage to striated muscles, skin and microcirculatory vessels.

ICD-10 code

• M33.0. Juvenile dermapolymyositis.

Epidemiology of juvenile dermatomyositis

The prevalence of juvenile dermatomyositis is 3.2 per 1,000,000 children under 17 years of age, with variations in different ethnic groups. The disease debuts at any age, but most often the onset occurs between the ages of 4 and 10 years. Girls are more often affected.

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Causes of Juvenile Dermatomyositis

The etiology is unknown. According to modern concepts, juvenile dermatomyositis is a multifactorial disease that develops as a result of antigen stimulation of an autoimmune response by the type of molecular mimicry under the influence of environmental factors, most likely in genetically predisposed individuals.

What causes juvenile dermatomyositis?

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Symptoms of Juvenile Dermatomyositis

The clinical picture of juvenile dermatomyositis is diverse, due to generalized damage to the microcirculatory bed, but the leading syndromes are cutaneous and muscular.

Classical skin manifestations of juvenile dermatomyositis are Gottron's sign and heliotrope rash. Gottron's sign is erythematous, sometimes flaky skin elements (Gottron's sign), nodules and plaques (Gottron's papules) rising above the skin surface of the extensor surfaces of the proximal interphalangeal, metacarpophalangeal, elbow, knee, and rarely ankle joints. Sometimes Gottron's sign is represented only by a dull erythema, which is subsequently completely reversible. Most often, erythema is located above the proximal interphalangeal and metacarpophalangeal joints and subsequently leaves scars.

Symptoms of Juvenile Dermatomyositis

Classification of juvenile dermatomyositis

Juvenile dermatomyositis is a separate form in the widely used classification of idiopathic inflammatory myopathies by A. Bohan and JB Peter. Juvenile dermatomyositis differs from adult dermatomyositis in that it has widespread vasculitis, severe myalgia, more frequent involvement of internal organs, high incidence of calcinosis, and no association with a neoplastic process (except for isolated cases).

Classification of idiopathic inflammatory myopathies according to A. Bohan and JB Peter (1975).

• Primary idiopathic polymyositis.
• Primary idiopathic dermatomyositis.
• Tumoral dermatomyositis/polymyositis.
• Juvenile dermatomyositis/polymyositis associated with vasculitis.
• Dermatomyositis/polymyositis in combination with other systemic connective tissue diseases.

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Diagnosis of juvenile dermatomyositis

The ECG reveals signs of metabolic disturbances in the myocardium, tachycardia. In myocarditis, conduction slowdown, extrasystoles, and decreased electrical activity of the myocardium are recorded. Occasionally, ischemic changes in the heart muscle are observed - a reflection of generalized vasculopathy affecting the coronary vessels.

Diagnosis of juvenile dermatomyositis

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Treatment of juvenile dermatomyositis

Patients with juvenile dermatomyositis are recommended early activation to prevent the development of severe muscular dystrophy, contractures and osteoporosis. As the disease activity subsides, dosed physical exercise (LFK) is prescribed. Massage is not performed until the inflammatory activity in the muscles has completely subsided. During the remission period, rehabilitation therapy is possible in special sanatoriums (sulfur, radon, brine baths) to reduce the severity of contractures.

How is juvenile dermatomyositis treated?

Prevention of juvenile dermatomyositis

Primary prevention of juvenile dermatomyositis has not been developed. To prevent relapses of the disease, an adequate reduction in the dose of basic drugs, primarily glucocorticosteroids, is of primary importance. The main factors leading to exacerbation of juvenile dermatomyositis are rapid reduction and premature withdrawal of glucocorticosteroids, insolation and vaccination, infectious diseases.

Forecast

In recent years, due to improved diagnostics and an expanded range of drugs, the prognosis for juvenile dermatomyositis has improved significantly. With timely initiation and adequate treatment, most patients can achieve stable clinical and laboratory remission. According to L.A. Isaeva and M.A. Zhvania (1978), who observed 118 patients, fatal outcomes were noted in 11% of cases, and profound disability in 16.9% of children. In recent decades, severe functional insufficiency has developed in juvenile dermatomyositis in no more than 5% of cases, and the proportion of fatal outcomes does not exceed 1.5%.

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