Juvenile arthritis: features of the clinical and instrumental picture and differential diagnosis

Juvenile arthritis in children (JRA) is a general name for a group of joint diseases in patients under the age of 16 years. Often this term refers to childhood rheumatoid arthritis, the main cause of disability in children and adolescents with musculoskeletal disorders.

In Russia, juvenile arthritis in children is quite common. According to statistics, every thousand child is affected by it. The disease does not spare even infants. Children's juvenile arthritis is more common among girls (about 2 times).

After the first episode, the disease progresses rapidly, so early diagnosis in juvenile arthritis is critical.

general information

Arthritis is accompanied by pain in the affected joints and is dangerous due to its complications. In some cases, the disease leads to the development of joint deformities or the formation of contractures. In the future, this may reduce the patient’s ability to work and cause disability.

According to statistics, 1 child in 1000 suffers from arthritis. Boys experience joint damage 2-3 times less often than girls. Pathology can occur in children from 0 to 18 years of age. However, patients under the age of 5-6 years are most often affected.

Regardless of their origin, arthritis is capable of triggering autoimmune processes in the body, which are characterized by a systemic nature. The pathogenetic links of the disease, in addition to the joints, begin to affect the skin, muscles and internal organs.

Classification

Based on the nature of the course and clinical picture, the following forms of the disease are distinguished:

• Pauciarticular arthritis . Usually develops in children 1-6 years old (mainly girls). Almost always affects the knee joints. In addition, inflammation of the choroid of the eyes (uveitis) develops. If treatment is started in a timely manner, the prognosis is favorable, and the patient experiences long-term remission. If the disease is not treated, polyarthritis and severe joint damage may develop.
• Juvenile rheumatoid polyarthritis is seronegative . It is more common in girls under 15 years of age. A large number of joints are affected, including the temporomandibular joint and the joints of the cervical spine. Rheumatoid factor is not detected in the blood. In its course, this form resembles the adult version of the disease. In most cases, the prognosis is favorable, but sometimes complications arise in the form of persistent dysfunction of the affected limb.
• Juvenile rheumatoid polyarthritis is seropositive . It usually develops in girls aged 8 years and older and affects various joints. The earlier the disease starts, the worse the prognosis, including disability. ANF ​​rheumatoid factor is present in the blood.
• Systemic rheumatoid arthritis . Does not depend on age and gender. The disease begins acutely, affecting the lymph nodes, joints, and internal organs. A high concentration of rheumatoid factor is found in the blood of patients.
• Idiopathic juvenile arthritis . Has unknown origin. Happens frequently. This diagnosis is made after excluding all other forms of the disease.

Classification: types of arthritis in children

There are a large number of different types of arthritis in children, each of which differs in its main features, course and prognosis.

• Juvenile rheumatoid arthritis (JRA). An autoimmune disease that often causes joint deformation and subsequent disability in adulthood.
• Rheumatoid arthritis. The disease is a consequence of the negative effects of streptococci. In addition to the joints, the cardiovascular system is often involved in the pathological process.
• Juvenile ankylosing spondylitis (Bechterew's disease). A rarer form of arthritis, accompanied by damage to the spine with the gradual development of its deformation.
• Reactive arthritis. A group of pathologies that are characterized by damage to the joints against the background of the activity of bacteria and viruses that multiply primarily in the gastrointestinal tract or urinary system of the patient.
• Infectious arthritis. They occur against the background of exposure to pathological microorganisms: bacteria, viruses, fungi, parasites.

The disease can be acute or chronic. The task of parents and doctors is to timely identify pathology and prevent its transition to a latent state. this approach reduces the risk of complications.

Classification of the disease

The following main types of arthritis in children are distinguished:

• Rheumatoid arthritis. It is one of the manifestations of rheumatism, the cause of its development is a previous streptococcal infection (scarlet fever, tonsillitis, pharyngitis).
• Juvenile rheumatoid arthritis. This is a chronic inflammatory disease of the joints of unknown origin. This pathology usually occurs in children under 16 years of age, has a progressive course, and can cause complications in internal organs. The main forms of juvenile arthritis are articular (one or more joints are affected) and systemic (the lungs, heart muscle, visual organs and a number of others are affected).
• Ankylosing juvenile spondylitis (another name for ankylosing spondylosis). Affects peripheral joints and spine and can occur in childhood.
• Infectious arthritis. Develops as a complication of bacterial, fungal, viral, and parasitic infections. The causative agents of the disease enter the joint through the blood and lymph, causing the development of an inflammatory process. In addition, pathogenic microflora can enter the joint as a result of injuries or improperly performed medical procedures.
• Reactive arthritis. This is a group of inflammatory aseptic joint pathologies that occur after an extra-articular infection.

Symptoms of arthritis in children

The main clinical symptom of all types of arthritis in children is pain in the affected joint.
Its characteristics may differ depending on the cause of the disease and the individual characteristics of the body. However, each disease has its own characteristics, such as its favorite location, intensity of pain, presence of joint deformities, etc. The table shows the differential diagnosis of articular syndrome in various arthritis. This will help parents navigate the variety of symptoms and, without missing anything, contact a pediatric rheumatologist in a timely manner.

In addition to articular syndrome, childhood arthritis may be accompanied by other symptoms:

• classic symptoms of inflammation - redness, swelling, decreased functional activity, increased local skin temperature over the lesion;
• fever up to 38-39oC;
• muscle pain;
• morning stiffness – the need to work out the affected joints after waking up;
• enlargement of nearby lymph nodes.

Decreased joint function can be manifested by lameness, inability to hold a pen, pencil, or perform household activities.

Symptoms of Juvenile Arthritis

JRA can occur in acute, subacute, chronic and chronic forms with exacerbations. Only a rheumatologist can accurately differentiate them. However, there are common symptoms of juvenile arthritis that are observed in all patients or in most patients:

• pain in the joints and sensitivity of the skin over them (in rare cases there is no pain);
• local increase in temperature of adjacent tissues;
• impaired biomechanics of the joint - movements become stiff, their amplitude is reduced until complete immobility (due to ankylosis - fusion of articular surfaces);
• swelling around the joint.

The disease makes itself felt not only in the joints. In children and adolescents there is:

• increase in general body temperature (possibly significant);
• fever and chills - may not leave the patient for months without treatment;
• muscle aches;
• rashes on the skin that do not itch and quickly disappear, but soon reappear.

Extra-articular symptoms are especially noticeable in the morning - this is their main difference from ordinary acute respiratory viral infections. Temperatures peak in the evening and at night. Dermatological manifestations on any part of the body increase as the pain intensifies and are absent during the period of remission.

The most alarming manifestations of systemic JA are:

• pain in the chest and in the area of ​​the heart, stomach, above the diaphragm;
• a feeling of suffocation that intensifies in a horizontal position;
• pallor or cyanosis of mucous membranes, face, fingers;
• swelling of the lower extremities, especially the ankle;
• suffocating cough, with or without phlegm;
• abdominal pain;
• due to loss of appetite, weight loss;
• painless enlargement of the lymph nodes (dense nodules about 5 cm in size are felt under the skin) while maintaining their mobility;
• enlargement of the liver and spleen, noticeable on palpation;
• eye complaints - redness of the conjunctiva and lacrimation, increased sensitivity to light, abnormal shape of the pupil, blurred and impaired vision (more often observed in girls under 12 years of age);
• psoriatic skin lesions that “fade” from the center to the edges.

In the later stages of the disease, joint deformation is observed due to thinning of the cartilage and grinding of the heads of the subchondral bones. JRA is also fraught with growth retardation, frequent bone and spine fractures, and the development of osteoporosis. In this case, the child grows poorly, limps, and complains of pain. The affected leg may be longer than the other, and the chin may take on a receding appearance.

Symptoms of juvenile arthritis are most often observed in the large and medium-sized joints of the extremities - ankle, knee, hip, elbow and wrist. Maxillotemporal arthritis and inflammation in the cervical spine are very characteristic of the disease. Arthritis of the interphalangeal and other small joints is relatively rare. JA can be either symmetrical or asymmetrical.

Causes of arthritis in children

Arthritis in children can be a consequence of the influence of both internal and external factors. Most often, the disease develops against the background of the following situations:

• Past viral or bacterial infections. Inflammatory processes in the digestive tract or urinary system are especially dangerous.
• Autoimmune disorders. Juvenile rheumatoid arthritis is a consequence of improper functioning of the immune system, when aggressive immune cells are formed against one's own tissues.
• Injuries and surgical interventions in violation of the rules of asepsis and antisepsis. Bruises, open fractures, and hematomas increase the risk of developing inflammation in the joint.
• Genetic predisposition. Predetermines reduced resistance of connective tissue to adverse external influences (connective tissue dysplasia is especially dangerous).
• Mechanical damage to intra-articular tissues due to obesity, too intense sports and the child lifting excessive weights.

General information about the disease

Arthritis of the hip joint (coxitis) is a polyetiological disease in the development of which many factors take part. There are several clinical forms of the disease, during which there are both similar and different symptoms. ICD-10 code M00 – M99.

The hip joint (HJ) is formed by the acetabulum of the pelvic bone and the head of the femur. The spherical shape makes it mobile; a ligament fits from the head of the femur to the acetabulum, holding the articular parts in a normal position. Externally, the hip joint is also strengthened by ligaments and a thick layer of soft tissue. This is the leading supporting joint, located deep in the tissues, so it is not so easy to identify a slow inflammatory process with mild symptoms in it.

Arthritis of the hip joint develops at any age, since the disease can have different origins. The most relevant clinical forms are lesions in childhood and adolescence, as well as tuberculous arthritis.

Expert opinion

Rheumatologists emphasize that arthritis in children is a very insidious disease that can lead to disability of the child. Persistent joint deformities can remain for life and thereby reduce the patient’s ability to work. That is why you need to contact a rheumatologist in time for specialized help aimed exactly at the target. Early initiation of therapy helps reduce the risk of complications. In addition, the duration of treatment in the initial stages of the disease is significantly shorter than in advanced cases.

Prognosis and prevention

JRA belongs to the group of lifelong diagnoses. Timely therapy and regular visits to a rheumatologist will help achieve stable remission without reducing the quality of life and severe restrictions in joint mobility. The risk of pathology transitioning to the acute stage is significant. An optimistic prognosis is formed with the early onset of the disease. Late manifestations of JRA are characterized by a continuously recurring course. The patient suffers from limited mobility of the limbs and becomes disabled.

Preventive measures involve parental supervision of young children to prevent excessive insolation or hypothermia. Children should limit contact with carriers of viral and bacterial infections.

Diagnosis of arthritis in children

Establishing a diagnosis of arthritis begins at the initial consultation stage. The doctor assesses the child’s general condition and details the complaints, conducts an examination and evaluates the functional activity of the affected joints.

To determine the cause of the disease, a rheumatologist prescribes laboratory and instrumental examination methods.

• General and biochemical blood test. The severity of the inflammatory process in the body is assessed.
• Blood test for inflammatory markers - antistreptolysin O, fibrinogen, C-reactive protein.
• Blood test for HLA-B27. This marker indicates ankylosing spondylitis.
• A blood test for citrullinated vimentin (MCV) is a marker of rheumatoid arthritis.
• Ultrasound of affected joints. The doctor evaluates the volume of synovial fluid, the size of the joint cavity, and the condition of the cartilage surfaces.
• X-ray of the affected joints. This study is necessary to assess the extent of bone tissue damage.
• MRI of joints. Indicated in difficult clinical cases.

Another effective diagnostic method is arthroscopy. This is an invasive endoscopic procedure that involves inserting a thin probe with a video camera at the end into the joint cavity. With its help, the doctor examines the pathological area from the inside. The main disadvantage of this procedure is its invasiveness. Therefore, arthroscopy is prescribed as a last resort when non-invasive examination methods cannot help in establishing an objective diagnosis.

If symptoms of damage to other organs and systems are detected, the child is examined by related specialists - a cardiologist, an orthopedist, an infectious disease specialist, an ophthalmologist.

Why is hip arthritis dangerous?

The hip joint is the largest joint in the body. It is the support of the human body. However, arthritis of the hip joint often goes unnoticed and leads to disability. The stages of the inflammatory process transform into one another and along with them the function of the hip joint is gradually lost. Therefore, during examination and diagnosis, the stage of the disease, possible complications and the tendency to relapse are identified.

Stages of hip arthritis

According to the degree of activity of the inflammatory process and its progression, there are 3 stages of arthritis of the hip joint:

1. Initial
   – inflammation of the synovial membrane, increased content of inflammatory exudate. At this stage, the restriction of movement is insignificant and occurs mainly due to pain and muscle spasm. On ultrasound, you can see an increased volume of exudate in the joint capsule.
2. Expanded
   . The degree of inflammation activity is high, and the first signs of a destructive process in the hip joint also appear. An X-ray can show narrowing of the joint space and bone loss (osteoporosis), and an MRI can show erosive damage to the cartilage tissue covering the articular surface. The pain is constant, movements are limited, mainly when extending the leg and turning it inward (rotation).
3. Advanced
   - formation of immobility (ankylosis). The bone tissue of the joint grows and fusion occurs into a single conglomerate. Often this fusion occurs in an incorrect position, which seriously limits movement. Complete disability occurs.

Possible complications

Arthritis of the hip joint can be complicated by:

• abscesses and fistulas (breakthrough of purulent exudate to the surface of the body) - with purulent and tuberculous hip arthritis;
• complete immobility of the joint;
• dislocations and subluxations of the hip joint;
• deformation of the entire skeleton against the background of pronounced changes in the hip joint.

To prevent this from happening, you should consult a specialist at the first signs of hip arthritis.

What to do if the disease relapses

Healthy and arthritic hip joint

Some clinical forms of this pathology occur in waves, with exacerbations and remissions. Exacerbations are rarely pronounced, but are still accompanied by pain. To eliminate pain before consulting a doctor, you can take the following measures:

• take any sedative (calming) agent - tincture of valerian or motherwort, Corvalol, etc.;
• take a tablet of medication from the group of NSAIDs (non-steroidal anti-inflammatory drugs) - Diclofenac, Nise, Indomethacin, etc.;
• apply ointment, gel or cream with NSAIDs to the skin over the sore spot (Voltaren, Pentalgin);
• call a doctor at home;
• lie down and take the least painful position.

Treatment of arthritis in children

Arthritis in children is a pathology that requires complex treatment, which depends on the type of disease, its cause and stage of development, the severity of the main symptoms and signs. In addition to relieving pain, the doctor is faced with the task of normalizing the function of the patient’s immune system and preventing the disease from becoming chronic in cases where this is possible. For this purpose, predominantly conservative treatment methods are used.

Conservative treatment

Regardless of the type of arthritis, conservative therapy is aimed at solving the following problems:

• elimination of pain and inflammation in affected joints;
• removal from the body of waste products of microorganisms that cause the disease;
• optimization of immune system function;
• restoration of function of the affected joint;
• preventing the development of contractures and deformities.

Achieving these goals with medications alone is not always possible. Therefore, rheumatologists use an integrated approach.

• Anti-inflammatory drugs. These include both conventional non-steroidal anti-inflammatory drugs and hormones. Sometimes patients are prescribed “heavy artillery” drugs—cytostatics. However, in pediatrics they try to avoid them due to side effects.
• Physiotherapy. The emphasis is on local anti-inflammatory and restorative procedures - UHF, magnetic therapy, ultrasound.
• Massage and exercise therapy.
• Balneotherapy, sanatorium-resort treatment.

The complex effect on the affected joints in particular and the body as a whole contributes to the activation of internal protective mechanisms and, consequently, faster recovery of the joints. With timely consultation with a doctor, it is possible to cope with the disease and prevent the development of complications.

Surgery

Surgeries for arthritis in pediatric practice are performed extremely rarely. They are indicated only for organic deformation of joints and persistent contractures.

Juvenile arthritis: features of the clinical and instrumental picture and differential diagnosis

Part 1

Juvenile arthropathy is a large isolated group of heterogeneous pathology of the musculoskeletal system of childhood, with similar pathogenetic mechanisms, but different in the nature of the clinical course and outcome of the disease. By their nature, arthropathy can be acute and chronic, septic and aseptic, primary or secondary to the development of the inflammatory process. The term “juvenile arthritis (JA)” refers to a group of primary chronic inflammatory diseases of the joints in children of unknown etiology, which are characterized by the same type of structural, morphological and functional changes. Arthritis lasting more than three months, the onset of the disease before the age of 16, and the exclusion of non-rheumatic joint pathology are the main criteria for establishing the diagnosis of juvenile arthritis. At the same time, chronic arthritis (synovitis) may be one of the manifestations of osteochondropathy, hereditary skeletal pathology, tumor or tumor-like formation of a joint, autoinflammatory syndrome, coagulopathy, infectious process, trauma and a number of other diseases. The variety of nosological forms, the similarity of the clinical and instrumental picture and the chronic nature of the course determine the group of arthropathy of childhood as one of the numerous and labor-intensive in diagnosis and choice of treatment tactics.

It is currently accepted that juvenile idiopathic arthritis (JIA) is a common chronic inflammatory joint disease in children of a multifactorial nature, which is characterized by a long progressive course, leading to the development of contractures and loss of joint function. The disease is based on a chronic progressive inflammatory process of the inner layer of the joint capsule (synovium), which leads to the destruction of cartilage and bone tissue. The prevalence of the disease in different countries ranges from 16 to 150 cases per 100,000 population. JIA is reliably more common than such well-known diseases as leukemia, diabetes mellitus, and inflammatory bowel diseases [1, 11, 19].

On different continents, a wide range of terms are used to refer to chronic arthritis in children - Still's disease, juvenile arthritis, juvenile rheumatoid arthritis (JRA), infectious nonspecific arthritis, juvenile chronic arthritis (JCA), deforming arthritis, juvenile idiopathic arthritis (JIA). In the Russian Federation, the term “juvenile arthritis” is only general and includes, according to the ICD X (International Classification of Diseases, 10th revision), only a few forms of arthritis: juvenile rheumatoid arthritis (JRA), juvenile chronic arthritis (JCA), juvenile ankylosing spondylitis ( JAS), psoriatic arthritis (PsA) and some others. Pediatric rheumatologists in most Western European countries successfully use three main classification systems for JA (Table 1) [3, 5].

According to the latest criteria of the International League of Associations for Rheumatology (ILAR, 2001, 2004), JIA includes several clinical forms of arthritis, grouped together into subgroups based on the nature of the course and outcome of the disease (ILAR, 2001, 2004). The clinical heterogeneity of JIA is determined by the multifactorial nature of the disease and develops on the basis of genetic predisposition under the influence of external environmental factors. Currently, the molecular basis of the development and maintenance of chronic inflammation in the joint is being actively studied. Recently, several dozen single nucleotide polymorphisms of “candidate genes” have been identified that are associated with various variants of the course of JIA (PTPN22, ERAP1, IL23R, P53, MDR1, etc.) [6–8, 22, 27].

Clinical picture of JIA

The pain syndrome has its own peculiarity and occurs exclusively with passive or active movements in the joints, while children at rest, as well as at night, do not complain of pain in the joints. In young children, when small joints of the hands and feet are affected, the pain syndrome may be completely absent. Morning stiffness, defined as a short-term lameness with sensations of severe tenderness in one or more joints, is a classic manifestation of a chronic inflammatory process involving the tendon-ligament apparatus. The degree of joint defiguration depends on the type and nature of the inflammatory process, namely exudative or exudative-proliferative synovitis, which is usually characterized by an increase in the volume of the joint. At the same time, proliferative-sclerotic lesions of the synovial membrane are more likely to develop a “dry synovitis” type. Edema can occur with any type of synovitis and, as a rule, is not strictly local in nature, except in cases of enthesopathy. Pathological sounds in the joints can be caused by the fluid part of the synovium itself, excessive proliferation of the synovial membrane, as well as the characteristic unevenness of the articular surfaces of the cartilaginous part of the epiphyses and patella. Blocks in the joints, pathological painful crunching or clicking, sensations of numbness are uncharacteristic symptoms for rheumatic pathology. The point of maximum pain, as a rule, is absent, and pain occurs both during palpation in the area of ​​​​the projection of the joint space and in the area of ​​​​the hypertrophied, inflamed synovium. Often, young children are not able to localize pain in the joint; swelling of the joint area may be poorly visualized due to the physiologically excessive subcutaneous fat layer, and the first signs of joint syndrome may only be limited movement or lameness. Any joint can be the target of juvenile arthritis, but large and medium-sized joints are most often affected, namely the knee, ankle, wrist, elbow, and hip; less often - small joints of the hands and feet. In severe variants of the disease, the “synovial joints” of the cervical spine and the temporomandibular joint are involved with the formation of arthrosis. The formation of contracture is progressive and in the early onset of the disease, a significant limitation in the range of motion is usually not typical [14, 17, 18, 20].

The term “oligo- or pauciarthritis” in the structure of JIA reflects a variant of joint damage in children, in which the inflammatory process affects no more than 4 joints during the first 6 months of the disease. This variant of articular damage occurs in 50–60% of cases and is characteristic exclusively of childhood. Often with oligoarthritis there is damage to the knee or ankle joint and the interphalangeal joint of the hand, and the latter is often visible. A quarter of children suffering from oligoarthritis have a picture of recurrent monoarthritis, described as “silent” arthritis, usually affecting the knee, less often the ankle joints, without signs of laboratory inflammatory activity. The early involvement of two or more joints in the inflammatory process greatly facilitates the diagnosis of arthritis. An abortive course of oligoarthritis with long-term remission is often observed. Oligoarthritis itself can be persistent or have a spreading form when new joints are involved (≥ 5 in total) 6 months after the onset of the disease. Persistent oligoarthritis is most typical for young girls with onset before the age of 6–8 years and is manifested by asymmetric (unilateral) damage to the joints of the lower extremities. The course of the disease is associated with an increased titer of antinuclear factor (more than 1/160), with a high risk of eye damage (rheumatoid uveitis or iridocyclitis), while, according to some data, up to 20% of children in this group may have asymptomatic uveitis. In other children, oligoarthritis may have a widespread course leading to polyarthritis, while the involvement of new joints may even occur in 2–3 years of the disease [15, 16, 21, 23, 25].

Articular damage in polyarthritis (more than 5 joints) is fundamentally different from oligoarthritis and is, as a rule, symmetrical in nature with the involvement of the joints of the upper and lower extremities, including the cervical spine and temporomandibular joints. The disease is more common among girls, but severe forms also occur among boys. There are two peaks of the disease: the first - from one to five years, the second - from ten to fourteen years. For young children, the most typical onset is with damage to one or two joints, with rapid involvement of more joints during the first six months of the disease. The first manifestations of arthritis may not be so bright, so the onset of JIA is often somewhat blurred. One of the manifestations of the disease at this age may be dactylitis with the subsequent development of polyarthritis. The presence of rheumatoid factor (RF) is not typical for this subgroup of children, but the degree of joint damage remains no less aggressive than in adults with RF+. At the same time, the risk of eye damage remains, which is closely related to an increased titer of antinuclear factor (ANF). For older children, the manifest onset of the disease is more typical, affecting several groups of joints simultaneously. Most often, the onset of polyarthritis is clinically manifested by arthritis of the small joints of the hands or feet, although later the disease can take a widespread form involving almost all groups of joints, including the cervical spine and hip joints. It is this subgroup that can be divided into two subtypes based on the presence of RF. Some children in this subgroup may be carriers of the HLADR4 gene and/or have antibodies to cyclic citrullinated peptide (anti-CCP), which, as some studies have shown, may directly reflect the degree of aggressiveness of the disease, but the proportion of such children is extremely small (less than 5%) . When the cervical spine is affected, anterior atlantoaxial subluxation, erosion of the odontoid process, arthritis of C1-C2 and apophyseal joints of the cervical spine most often develop, which is a distinctive feature of this pathology [8, 9, 12].

Systemic arthritis may not have a persistent articular syndrome or a picture of oligo-polyarthritis, but is manifested by hectic fever, skin syndrome, lymphadenopathy, polyserositis and hepatosplenomegaly. The systemic inflammatory process occurs with an extremely high degree of laboratory activity in the form of leukocytosis, thrombocytosis, increased levels of transaminases, progressive anemia, significant acceleration of ESR, high levels of CRP, and dysproteinemia. Articular syndrome at its onset may be limited to arthralgia or intermittent exudative arthritis of the joints of the upper or lower extremities. Persistent arthritis can develop several months after the onset of the disease or even after one or two years of illness. Often there is asymptomatic involvement of the hip, temporomandibular joints and joints of the cervical spine with the development of multiple arthrosis. With a long period of illness, most children, as a rule, have polyarthritis and bilateral aseptic necrosis of the femoral heads. One of the main life-threatening complications of systemic arthritis is the development of macrophage activation syndrome (MAS). This complication occurs with a frequency of 6.7–13%, and the mortality rate, according to various sources, is up to 22%. This complication is based on the uncontrolled activation of macrophages and T-lymphocytes with systemic hyperproduction of cytokines, which is clinically manifested by pancytopenia, liver failure, coagulopathy and neurological symptoms [10, 24, 26].

One of the variants of the course of JIA is a combined articular lesion of the “synovitis + enthesitis” type, or isolated enthesitis. According to the proposed ILAR criteria, this group of patients should be classified into the group of JA with enthesopathy, which can also include children with seronegative enthesoarthropathy (SEA syndrome). The prevalence of the enthesitic nature of the lesion determines a relatively “favorable” variant of the course of the disease, provided there is no erosive process and sacroiliitis. Involvement of sacroileal joints in the process and the presence of the HLA-B27 gene indicate a possible variant of articular damage such as spondyloarthropathy. The joints that are most often involved in the inflammatory process in “rheumatic enthesopathy” are the hip, ankle, and knee; less often - shoulder and elbow [13].

Juvenile spondyloarthritis is a separate group of rheumatic diseases of childhood, which includes juvenile ankylosing and undifferentiated spondylitis, psoriatic arthritis, arthropathy in chronic inflammatory bowel diseases (Crohn's disease, ulcerative colitis), Reiter's syndrome and other reactive arthritis of urogenital and postenterocolitic nature. A distinctive feature of spondyloarthropathies is the prevalence of males, frequent carriage and familial aggregation of the HLA-B27 gene, combined joint damage of the “synovitis + enthesitis” type with involvement of the spine. Articular damage in psoriatic arthropathy can precede psoriasis and occur in severe form, such as oligo- or polyarthritis with multiple erosions. Characteristics of PsA are arthritis of the distal interphalangeal joints, dactylitis, mutilating arthritis with the development of osteolytic syndrome, as well as psoriatic onycholysis. Dactylitis is a type of articular lesion that clinically manifests itself as a “sausage-shaped” deformation of the fingers of a limb due to simultaneous inflammatory damage to the tendon-ligamentous apparatus and interphalangeal, metacarpophalangeal or metatarsophalangeal joints [4].

In addition to the classification of juvenile arthritis according to the number of affected joints, in order to determine the variant of the course and predict the outcome of the disease, other proposed criteria are also used: determining the stage of anatomical changes, functional disorders and the degree of laboratory (inflammatory) activity.

Diagnosis of juvenile arthritis

Today, screening for instrumental diagnostics of joint pathology includes radiographic examination and ultrasound scanning. The initial assessment of the obtained instrumental examination data and comparing them with the clinical picture is one of the main tasks of the attending physician. However, due to the numerous nosological forms of joint pathology, specialists in the field of orthopedics and rheumatology are increasingly having to resort to additional examination methods. The most popular and diagnostic significance among specialists are magnetic resonance and computed tomography, arthrography, three-phase osteoscintigraphy and diagnostic arthroscopy with biopsy of the synovial membrane. However, the availability and commercial component of these types of studies limit their use in the outpatient setting; moreover, diagnostic arthroscopy is a full-fledged surgical intervention. Therefore, the initial assessment of the nature of the articular lesion should be based on simple and cheap instrumental methods, such as radiography and ultrasound scanning, during the assessment of which the doctor should clearly define the goals and methods of additional diagnostics.

As is known, JIA is a chronic inflammatory disease of the synovial membrane, spreading to all structures of the joint, including bone and cartilage tissue. Instrumental diagnostics are based on methods of visualizing the characteristic signs of a chronic inflammatory process, the assessment of which should take into account the existing number of anatomical and physiological features of bone and cartilage tissue in children. The X-ray image of the bones and joints of children differs from their image in adults in a number of features that are characterized by continuous stages of enchondral bone formation, which determines modifications in the shape and contour of a certain part of the bones, the structure of the bone tissue itself. The response of bone tissue in children to the course of a chronic inflammatory process is characterized by the rapid development of osteoporosis, asymmetry and uneven ossification of cartilaginous patterns, as well as accelerated growth of the epiphyses that form the joint. The formation of foci of bone tissue degeneration and areas of aseptic necrosis is not uncommon. Specific changes in the bone tissue of joints susceptible to RA allowed Steinbrocker in 1988 to systematize the X-ray data and present them as stages of anatomical changes, which have also found wide application in pediatric practice:

• Stage I. Epiphyseal osteoporosis, compaction of periarticular soft tissues, accelerated growth of the epiphyses of the affected joints.
• Stage II. The same changes plus narrowing of the joint space, isolated bone lesions (erosions).
• Stage III. Widespread osteoporosis, severe osteochondral destruction, dislocations, subluxations, systemic disturbance of bone growth.
• Stage IV. Changes inherent in stages I–III and fibrous, bone ankylosis.

Differential diagnosis of mono- and oligoarthritis in children

As a rule, the greatest difficulties in diagnosing arthritis and arthropathy in childhood are caused by the monoarticular variant of the lesion. A monotonous or recurrent course of arthritis, the absence of involvement of new joints over a long period of observation, minimal or, conversely, high laboratory inflammatory activity that does not correspond to the degree of joint damage, as well as the early development of foci of bone destruction are the main signs of an atypical course of rheumatic pathology. Under the guise of monoarthritis with a “bright” debut, acute hematogenous osteomyelitis and septic arthritis, an osteochondral tumor, can occur. In addition, post-infectious arthritis, post-traumatic arthropathy and hemarthrosis, and less commonly, osteochondropathy and oligoarthritis in the structure of JA may have an acute onset. The erased onset and chronic course of monoarthritis is characteristic of a wider range of articular pathologies. Chronic synovitis, and sometimes “simulation” of this type of inflammation can be one of the manifestations of diseases such as tuberculous arthritis, pigmented villous nodular synovitis, synovial chondromatosis, chondroblastoma, osteoid osteoma, vasculitis, PAPA syndrome, Blau syndrome, Gaucher disease, Fabry, superficial venous dysplasia, cavernous hemangioma, some forms of osteochondropathy and a number of other rare monogenic syndromes. To date, the role of cytokine-dependent mechanisms (TNF-α, IL-1, IL-6) in the development of chronic inflammation of the synovial membrane has been proven not only for rheumatic pathology, but also in cases of aseptic necrosis, tumors of osteochondral tissue, lysosomal storage diseases and a number of monogenic syndromes. In other types of arthropathy, irritating mechanical effects on the synovial membrane or its chronic trauma can lead to the development of an inflammatory reaction [2, 11, 13, 16, 18, 19].

The range of differential diagnosis of mono- and oligoarthritis in children is presented in Table. 2 and 4.

Diagnosis and treatment of purulent-inflammatory diseases of the skeleton in children remain very pressing problems, in particular for pediatrics and pediatric surgery. Often, osteomyelitis, as well as septic arthritis, can be a difficult to diagnose pathology in children in the early stages, despite a wide range of imaging methods. Over the past decade, there has been an increase in the number of diseases with atypical and severe forms, which often leads to the development of complications and increased disability. In addition, the nature of the clinical course and instrumental signs of osteomyelitis have their own characteristics in children depending on age. It is believed that osteomyelitis is an inflammation of the bone marrow and adjacent bone tissue of a local or widespread nature with the formation of a necrotic focus - sequestrum. In some countries, osteomyelitis occurs with a frequency of 2 to 13 per 100,000 children, the frequency of septic arthritis is 2–3 times less common. Osteomyelitis can be acute or chronic, by the nature of the infectious agent - specific or nonspecific, by the route of penetration - exogenous or endogenous. Acute osteomyelitis is characterized by the development of a focus of bone necrosis in areas rich in blood supply, with a dense network of anastomoses - these are the areas of the metaphyses and epiphyses. For children under two years of age, excluding newborns, the epiphyseal form of osteomyelitis with a picture of septicemia is more typical, while for older children - the metaphyseal form, the course of which may have a local form. An early radiological picture of the formation of a necrosis focus is observed in children from the 3rd to the 10th day from the onset of the disease. Chronic osteomyelitis in children, as a rule, is a consequence of untreated acute osteomyelitis or occurs secondarily in areas of altered bone tissue. However, changes in immune homeostasis and environmental factors play a major role in the occurrence of chronic osteomyelitis. The most common targets of chronic osteomyelitis are long bones.

Diagnosis of osteolytic pathology often presents difficulties in cases of sluggish nature of the inflammatory process due to the polymorphism of the clinical and instrumental picture. The use of spiral computed tomography, magnetic resonance imaging, and three-phase osteoscintigraphy does not always make it possible to make the correct diagnosis, so in some cases a focus biopsy is crucial (Fig. 1).

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A. N. Kozhevnikov*, 1, Candidate of Medical Sciences N. A. Pozdeeva*, Candidate of Medical Sciences M. A. Konev* V. V. Selizov* A. V. Moskalenko* K. A. Afonichev*, Doctor of Medical Sciences G. A. Novik**, Doctor of Medical Sciences, Professor

* Federal State Budgetary Institution Scientific Research Institute for Children's Orthopedics named after. G. I. Turner, Ministry of Health of the Russian Federation, St. Petersburg ** State Budgetary Educational Institution of Higher Professional Education, St. Petersburg State Medical University, Ministry of Health of the Russian Federation, St. Petersburg

1 Contact information

Prevention of arthritis in children

Prevention of arthritis involves eliminating provoking factors. Of course, no one can change their own DNA yet. However, you can treat a sore throat in time, avoid contact with people sick with ARVI, rationalize physical activity, avoiding unbearable overexertion.

If you have relatives with arthritis in your family, it is recommended to visit a rheumatologist at least once a year and undergo a basic set of tests to identify preclinical changes. This will allow you to start therapy on time if pathology is diagnosed.

Questions

• Which doctor treats arthritis in children?
  A pediatric rheumatologist diagnoses and treats arthritis.
• Do arthritis always cause deformities?
  Persistent deformities are characteristic of juvenile rheumatoid arthritis and ankylosing spondylitis. However, they do not always occur. The basis for preventing deformation is timely consultation with a doctor and targeted treatment.
• Is it possible to cure arthritis with folk remedies?
  Traditional medicine is not a scientifically proven form of treatment. This means that it is not possible to predict the effect of certain medicinal plants on the child’s body. Using traditional medicine methods, precious time is lost, and the pathological process can take an aggressive course. To effectively combat arthritis, the use of medications aimed at interrupting the vicious circle of changes in the body is required. Traditional medicine can act as an auxiliary therapy, but not a basic one, and only after consultation with your doctor.
• Is it always necessary to take “hormones” for arthritis in children?
  Hormonal therapy is prescribed to children only with certain forms of arthritis if there are absolute indications.

Treatment of juvenile rheumatoid arthritis

Non-drug treatment:

• Physiotherapy.
• Balanced diet: fruits, vegetables, foods rich in polyunsaturated fatty acids.

Drug treatment:

• Non-steroidal anti-inflammatory drugs.
• Glucocorticosteroids.
• Disease-modifying antirheumatic drugs.
• Biological preparations (R – Mab).
• Targeted synthetic drugs.

To better achieve a therapeutic effect, it is necessary to prevent infectious diseases, avoid hypothermia and stress. Home education is recommended for children with systemic onset of JRA and during periods of exacerbation of the disease.

Sources

• Rheumatology: Clinical guidelines / ed. Academician RAMS E.L. Nasonova. – 2nd ed., rev. and additional - M.: GEOTAR-Media, 2010. - 752 p.
• Assier E., Boissier M.-C., Dayer J.-M. Interleukin-6: from identification of the cytokine to development of targeted treatments. Joint Bone Spine 2010;77(6):532–6.
• Nam JL, Winthrop KL, van Vollenhoven RF et al. Current evidence for the management of rheumatoid arthritis with biological disease-modifying antirheumatic drugs: a systemic literature rewires informing the EULAR recommendations for the management of RA.

Frequently asked questions about the disease

Which doctor should I contact?

It’s better to start with a therapist, he will advise who to contact. A surgeon treats purulent processes, a rheumatologist - everything else, except for tuberculosis, you need to contact a phthisiatrician.

Can juvenile arthritis be cured without surgery?

With adequate treatment, you can get rid of relapses of the disease and its progression. Modern methods of conservative treatment allow patients to forget about exacerbations forever during maintenance treatment. Surgery is a last resort, but sometimes it is still necessary.

Literature:

1. Yablokova E. A. Clinical features and impaired mineralization of bone tissue in children with inflammatory bowel diseases. Diss. Ph.D. honey. Sci. M., 2006. 185.
2. Dzyuba G.G., Reznik L.B., Erofeev S.A., Stasenko I.V. Modern methods of treating surgical infection of the hip joint // Modern problems of science and education. – 2021. – No. 5.
3. D'Incà R., Podswiadek M., Ferronato A., Punzi L., Salvagnini M., Sturniolo GC Articular manifestation in inflammatory bowel disease patients. A prospective study // Dig Liver Dis. 2009, Mar 9.
4. Rodriguez VE, Costas PJ, Vazquez M., Alvarez G., Perez-Kraft G., Climent C., Nazario CM Prevalence of spondyloarthropathy in Puerto Rican patients with inflammatory bowel disease/Ethn Dis. 2008, Spring; 18(2 Suppl 2):S2–225–9.

Themes

Arthritis, Joints, Pain, Treatment without surgery Date of publication: 12/09/2020 Date of update: 03/12/2021

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