Symptoms of juvenile dermatomyositis

Symptoms of juvenile dermatomyositis are diverse due to the generalized lesion of the microcirculatory bed, but the leading syndromes are cutaneous and muscular.

Skin Changes

Classic skin manifestations of juvenile dermatomyositis - a symptom of Gottron and heliotrope rash. Gottron's symptom is erythematous, sometimes flaky skin elements (Gotthron's feature), nodules and plaques (Gottron's papules) that rise above the surface of the skin of the extensor surfaces of proximal interphalangeal, metacarpophalangeal), elbows, knees, and rarely ankle joints. Sometimes Gottron's symptom is represented only by a mild erythema, subsequently completely reversible. Most often, the erythema is located above the proximal interphalangeal and metacarpophalangeal joints and subsequently leaves behind the scars.

Classical heliotrope rash with juvenile dermatomyositis - lilac or erythematous periorbital skin eruptions on the upper eyelids and space between the upper eyelid and eyebrow (a symptom of "purple glasses"), often in combination with periorbital edema.

Erythematous rash is also on the face, chest, neck (V-shaped), upper back and upper arms (symptom of "shawl"), abdomen, buttocks and thighs. Often in patients, a tree-like liver in the region of the shoulder girdle and proximal parts of the extremities is identified (which is typical for young patients), possibly on the face. The pronounced vasculopathy leads to the formation of superficial erosions, deep skin ulcers, causes residual hypopigmentation, atrophy, telangiectasia and sclerosis of varying severity. The early sign of the disease is changes in the nail bed (hyperemia of the peri-oral grooves and growth of the cuticle).

Skin manifestations of juvenile dermatomyositis precede muscle damage for several months or even years (on average for six months). Isolated skin syndrome in the debut is met more often than the muscular or muscular-dermal. However, in some cases, these skin manifestations appear months after the debut of myopathy.

Skeletal muscle damage

The cardinal symptom of juvenile dermatomyositis is the symmetrical weakness of the proximal muscle groups of the extremities and muscles of the trunk of varying degrees of severity. Most often affected muscles of the shoulder and pelvic girdles, flexors of the neck and muscles of the abdominal press.

Usually parents start to notice that the child has difficulties in performing actions that previously did not cause problems: climbing the stairs, getting up from a low stool, bed, pot, floor. It is difficult for a child to sit on the floor from a standing position; He has to lean on a chair or his knees to pick up a toy from the floor; when he gets out of bed he helps himself with his hands. Progress of the disease leads to the fact that the child does not hold his head well, especially when he lies down or gets up, can not dress himself, brush his hair. Often parents consider these symptoms to be a manifestation of general weakness and do not fix their attention to them, so when collecting an anamnesis, they should be asked to question them about it. With severe muscle weakness, the child often can not tear off the head or leg from the bed, sit down from a lying position, in more severe cases - can not walk.

The damage to the eye muscles and distal limb muscle groups is not typical. Involvement of the distal muscles of the extremities is found in young children or in severe and acute disease.

The terrible symptoms of juvenile dermatomyositis are a defeat of the respiratory and swallowing muscles. Involving of intercostal muscles and diaphragm leads to respiratory failure. With the defeat of the muscles of the pharynx, dysphagia and dysphonia occur: the timbre of the voice changes-the child begins to nasalize, swallow, difficulties arise when swallowing hard and sometimes liquid food, rarely liquid food pours out through the nose. Dysphagia can lead to aspiration of food and cause the development of aspiration pneumonia or directly lethal outcome.

Often, patients complain of muscle pain, although weakness may not be accompanied by pain syndrome. In the debut and the height of the disease during examination and palpation, it is possible to identify in the patient dense edema or the density and tenderness of the muscles of the extremities, mainly proximal ones. Symptoms of muscle damage can precede skin manifestations. However, if the skin syndrome is absent for a long time, then we are talking about juvenile polymyositis, which is 17 times less common than juvenile dermatomyositis.

Inflammatory and necrotic processes in muscles are accompanied by dystrophic and sclerotic changes leading to muscular dystrophy and the formation of tendon-muscle contractures. With a moderately pronounced process, they develop in the elbows and knee joints, with heavy flow are widespread. Timely treatment begun leads to a complete regression of contractures. Long-term untreated inflammatory process in muscles, on the contrary, causes persistent changes that cause disability of the patient.

The degree of muscular dystrophy and atrophy of subcutaneous fat (lipodystrophy) is directly proportional to the duration of the disease before treatment and is most typical for the primary-chronic variant of juvenile dermatomyositis, when the diagnosis is late and treatment begins several years after the onset of the disease.

Soft tissue injury

Calcification of soft tissues (mainly muscles and subcutaneous fatty tissue) is a peculiarity of the juvenile variant of the disease, it develops 5 times more often than with adult dermatomyositis, especially often in preschool age. Its frequency varies from 11 to 40%, often amounting to about 1/3 of patients; developmental period - from 6 months to 10-20 years from the onset of the disease.

Calcinosis (limited or diffuse) - deposits of calcium salts (hydroxyapatites) in the skin, subcutaneous adipose tissue, muscles or intermuscular fascia in the form of single nodules, large tumorous formations, surface plaques or common. With superficial location of calcifications, inflammatory reaction of surrounding tissues, suppuration and rejection of them in the form of crumbly masses is possible. Deeply located muscular calcifications, especially single ones, are detected only by X-ray examination.

The development of calcification in juvenile dermatomyositis reflects the degree of severity, prevalence and cyclicity of the inflammatory necrotic process. Calcium is more likely to develop with delayed initiation of treatment and, according to our data, is 2 times more likely to recur in the course of the disease. Its appearance heavies the forecast due to the frequent infection of calcifications, the development of joint-muscle contractures in the case of their location near the joints and in the fascia.

Lesion of joints

Articular syndrome with juvenile dermatomyositis is manifested by arthralgia, restriction of mobility in the joints, morning stiffness in both small and large joints. Exudative changes are less common. As a rule, changes in the joints regress on the background of treatment and only rarely, in the case of lesions of small joints of the hands, leave behind a spindle-shaped deformation of the fingers.

Heart Attack

Systemic muscular process and vasculopathy cause frequent involvement in the pathological process of the myocardium, although in juvenile dermatomyositis, all 3 cores of the heart and coronary vessels can suffer, up to the development of myocardial infarction. However, the low severity of clinical symptoms and their non-specificity explain the difficulty of clinical diagnosis of carditis. In the active period, patients develop tachycardia, muffled heart tones, widening the boundaries of the heart, and disturbing the heart rhythm.

Lesion of the lungs

The defeat of the respiratory system with juvenile dermatomyositis is often met, which is primarily due to the involvement of respiratory muscles (with the development of respiratory failure) and pharyngeal muscles (with swallowing and possible development of aspiration pneumonia). At the same time, there is a group of patients with lesions of interstitium of mild varying degrees - from an intensification of the pulmonary pattern on the radiograph and the absence of clinical symptoms to a severe, rapidly progressing interstitial process (the type of fibrotic alveolitis of Hamon-Rich). In these patients, pulmonary syndrome acquires a leading role in the clinical picture, is difficult to treat with glucocorticosteroids and determines an unfavorable prognosis.

Lesion of the gastrointestinal tract

The main cause of gastrointestinal tract damage in juvenile dermatomyositis is a widespread vasculitis with the development of trophic disorders, a violation of innervation and a lesion of smooth muscles. Always alarming in the clinic of dermatomyositis in children the appearance of complaints of pain in the throat and along the esophagus, worse when swallowed; pain in the abdomen, wearing an unsharp, diffuse nature. The basis of the pain syndrome can be several reasons. The most serious causes are esophagitis, gastroduodenitis, enterocolitis, caused by both catarrhal inflammation and erosive-ulcerative process. In this case, minor or profuse bleeding occurs (melena, bloody vomiting), perforations leading to mediastinitis, peritonitis and, in some cases, to the death of a child, are possible.

Other clinical manifestations

Juvenile dermatomyositis is characterized by lesions of the mucous membranes of the oral cavity, less often the upper respiratory tract, conjunctiva of the eye, vagina. In the acute period, a moderate increase in the liver, poly-lymphadenopathy is usually found with the concomitant infectious process. With active juvenile dermatomyositis, the development of polyserositis is possible.

Approximately 50% of patients experience a subfebrile fever reaching febrile numbers only with the concomitant infectious process. In acute and subacute course of the disease, patients complain of malaise, fatigue, weight loss. In many patients, more often younger age, they observe irritability, tearfulness, negativism.

Variants of juvenile dermatomyositis, proposed by LA. Isaeva and M.A. Zhvania (1978):

• sharp;
• subacute;
• primary chronic.

The acute course is characterized by a violent onset (the severe condition of the patient develops within 3-6 weeks) with high fever, bright dermatitis, progressive muscle weakness, swallowing and breathing disorders, pain and edema syndrome, visceral manifestations. Acute illness is observed in about 10% of cases.

In subacute flow, a complete clinical picture appears within a few months (sometimes within a year). The development of symptoms is more gradual, the temperature is subfebrile, visceral lesions are less common, calcification is possible. Subacute flow is characteristic for the majority of patients (80-85%).

For the primary chronic course (5-10% of cases), the gradual onset and slow progression of symptoms over several years in the form of dermatitis, hyperpigmentation, hyperkeratosis, and minimal visceral pathology are characteristic. The prevalence of general dystrophic changes, atrophy and sclerosis of muscles, a tendency to develop calcifications and contractures.

Degrees of process activity:

• I degree;
• II degree;
• III degree;
• crisis.

The separation of patients according to the degree of activity of the process is carried out on the basis of the severity of clinical manifestations (primarily, the degree of muscle weakness) and the level of increase in "enzymes of muscle decay".

Myopathic crisis - the extreme severity of the defeat of striated muscles, including respiratory, laryngeal, pharyngeal, diaphragmatic, etc .; the basis is necrotic panmiositis. The patient is completely immobilized, myogenic bulbar and respiratory paralysis develop, creating a life-threatening situation due to respiratory failure of the hypoventilation type.

[1], [2], [3], [4], [5], [6], [7]