Symptoms of juvenile ankylosing spondylitis

Because juvenile ankylosing spondylitis is a prototype for the entire group of juvenile spondyloarthritis, its inherent clinical manifestations occur with all the diseases of this group in the form of separate symptoms or their combinations.

60-70% of children become ill with juvenile spondyloarthritis over the age of 10, however, in rare cases an early onset (up to 7 years) occurs, the debut of juvenile ankylosing spondylitis at the age of 2-3 years is described. The age of the onset of the disease determines the spectrum of clinical manifestations in the onset of juvenile ankylosing spondylitis and the pattern of its further course.

The clinical symptom complex of juvenile ankylosing spondylitis consists of four main syndromes:

• peripheral arthritis (more often oligoarthritis with predominant lesion of the lower limbs, usually asymmetric);
• enthesopathies - inflammatory changes in the places of attachment of tendons and ligaments to bones;
• extraarticular manifestations with a typical lesion of the eyes, heart, mucous membranes, skin, possible involvement of internal organs (eg, IgA-associated nephropathy);
• defeat of the axial skeleton - joints, ligaments and other anatomical structures of the spine and adjacent articulations (sacroiliac, lobular, sternoclavicular, clavicular-acromic, sternocostal, rib-vertebral, manubrio-lateral).

Variants of the debut of juvenile ankylosing spondylitis Depending on the primary localization of the pathological process, several variants of the debut are conventionally distinguished:

• isolated peripheral arthritis;
• a combination of arthritis and enthesitis (SEA-syndrome);
• simultaneous lesion of peripheral joints and axial skeleton (in 1/4 patients);
• isolated entesite;
• isolated lesion of the axial skeleton;
• isolated eye damage.

The first three options for debut occur in 90% of patients, while the last three - in rare cases and only in children older than 10 years.

Within the childhood and adolescence, the course of juvenile ankylosing spondylitis is generally relatively benign, predominantly relapsing. Long-term remissions are characteristic, the duration of which sometimes reaches 8-12 years. However, as the child grows up, the disease acquires a chronic, progressive nature of the course, especially due to the growing symptoms of axillary skeleton and coxitis, in the long term, juvenile ankylosing spondylitis has a more severe prediction in comparison with ankylosing arthritis.

Peripheral arthritis

The main clinical features of peripheral arthritis in adolescent spondyloarthritis:

• oligoarticular or limited polyarticular lesion,
• asymmetry;
• primary lesion of the joints of the lower limbs;
• combination with enthesitis and other tendon-ligamentous symptoms;
• non-destructive character (with the exception of tarzite and coke);
• relatively benign course with the possibility of complete reverse development and a propensity to develop long-term, including long-term remissions.

The most frequent localization of peripheral arthritis is knee and ankle joints. If the asymmetric character of the articular syndrome is clearly expressed, or arthritis proceeds most persistently only in one joint and much less in others, irritation of the epiphyseal growth zones (most often in the knee joint) often leads to lengthening of the affected limb. This mechanism for the formation of a difference in length should be distinguished from the relative shortening of the leg in arthritis of the hip joint, which can result from several reasons: flexion-causing contracture, subluxation or destruction of the femoral head. Coxit is prognostically the most serious manifestation of peripheral arthritis, which can lead to disability of patients and cause the need for endoprosthetics in a relatively short time.

The defeat of the tarsal joints with the formation of the so-called ankylosing tarsitis is a typical clinical symptom of the juvenile spondyloarthritis disease in children, especially juvenile ankylosing spondylitis. This peculiar defeat of the articular and tendon-ligamentous apparatus of the foot is clinically manifested by a pronounced defoguration of the tarsus region, usually with a significant pain component, a change in the coloration of the skin due to inflammatory changes, is usually combined with lesions of periarticular soft tissues (Achillesburyitis, plantar fasciitis, tenosynovitis in the region external and internal ankle), is accompanied by gait disturbance, sometimes up to loss of limb's ability to support. Roentgenologically, tarsit is manifested by osteopenia, often sharply expressed, by erosion of articular surfaces of tarsal bones, sometimes in combination with bone growths and periosteal stratifications, and in the course of prolonged course - the development of ankylosis in the tarsal joints. The presence of such an articular lesion allows almost completely to exclude the diagnosis of juvenile rheumatoid arthritis and predict the development of a spondyloarthritis in a patient.

At any stage of the development of the disease, it is possible to involve any joints in the pathological process, although there is a tendency to predominance of arthritis of the lower limbs and affection of the cartilaginous joints related to the structures of the axial skeleton: sternocleid. Clavico-acromial, rib-sternal, manubrio-sternal, pubic articulations, etc. Some patients may have an isolated lesion of the joints of the first finger of the hand, which usually does not bother the child, but this is revealed during clinical examination.

Formally, peripheral arthritis is rarely limited to truly oligoarticular lesions and often affects more than five joints, however, the persistence of arthritis occurs only in a certain number of joints. In most patients, the joint syndrome is unstable and subsequently undergoes a complete reverse development, often without any residual changes. Torpid flow of arthritis is characteristic for hip, ankle and tarsus joints, to a lesser extent - knee and first toes, and usually in those joints with lesions whose debut disease.

Peripheric arthritis in other joints is predominantly non-erosive, however, in 10% of patients, destructive cocksite may appear, the nature of which is fundamentally different from the destructive coxite in "classical" juvenile rheumatoid arthritis. In contrast to the aseptic necrosis of the femoral head heads peculiar to juvenile rheumatoid arthritis, especially its systemic variant, with osteolysis and fragmentation of the head, almost never develops with juvenile ankylosing spondylitis. Characteristic features of destructive coxitis in juvenile ankylosing spondylitis - a tendency to gradual narrowing of the hip joint with the development of ankylosis, bone proliferation. In some patients, juvenile spondyloarthritis may cause single erosions in the distal parts of the feet with localization, as a rule, at the attachment points of the joint capsule, which is essentially a variant of enthesopathy.

Peripheral arthritis in adolescent spondyloarthritis is often associated with lesions of periarticular tissues in the form of tenosynovitis, tendinitis, and various localization of enthesopathies, which serve as a rather specific manifestation of juvenile arthritis spondylitis.

Enterospaties (extraarticular musculoskeletal symptoms)

Most authors note that in children this sign is detected much more often than with ankylosing adult spondylitis, and the incidence of enteropathy is 30-90%, and about 1/4 of patients have these symptoms already in the debut. Attachment of this symptom is possible at almost any stage of the disease, but it is rarely found in patients under 10 years old.

The preferred localization of enthesopathies is the area of the heel bones. Manifestality of clinical manifestations of Achillobursitis and subclavian bursitis facilitates their detection, whereas for the detection of enterosopathies of other localization, a thorough physical examination is necessary. Palpatory tenderness in the places of attachment of ligaments and tendons of muscles to bones, as well as signs of tendinitis, are most often found in the region of tuberosity of tibia, patella, external and internal ankles, metatarsal bones, large and small trochanteres, iliac crests, sciatic tubercles, , elbow processes. In practice, it is possible to observe tendon-ligamentous symptoms of an unusual nature, in particular, with localization in the area of the puarth ligament, which can be accompanied by intense pain and local muscle tension in the inguinal area, simulating acute surgical pathology. In rare situations, it is possible to manifest ossifying tendonitis in the region of the occipital mounds.

X-ray signs of enthesopathies are most often represented by osteophytes along the lower edge of the heel of the calcaneus, or by erosion of the bone at the sites of fixation of the tendons, the initial signs of which allow revealing computer and MRI. In isolated cases erosions and periostitis are possible in the region of crests of the iliac, ischium bones, skewers and other places of enthesites.

Specific manifestations of entesite include dactylite, expressed in a "sausage-shaped" finger deficit due to simultaneous inflammatory involvement of the joint and tendon-ligament apparatus, which occurs both on the upper and lower extremities. Dactylitis is a typical symptom of juvenile psoriatic arthritis, but it can also be found in other juvenile spondyloarthritis. With the persistent nature of dactylitis, it is possible to develop a periosteal reaction requiring differential diagnosis with non-rheumatic conditions. Typical for juvenile spondyloarthritis pain in the buttock area is usually associated with inflammation in the sacroiliac joints, however, there are data that explain this symptom by the involvement of periarticular soft tissues and polyanthesis in the pathological process.

Extrarcticular manifestations

Eye damage is one of the most significant extraarticular symptoms of juvenile ankylosing spondylitis, most often represented by acute anterior uveitis (iridocyclitis) occurring in 7-10% of patients in childhood and 20-30% in adolescent and adult. Typical bright clinical symptoms with sudden reddening of the eyeball, pain and photophobia, but in some patients may be a small-symptom course of uveitis. In isolated cases, the pathological process affects all parts of the choroid (panoveitis), not limited only to the anterior segment of the uveal tract. With rare exceptions, uveitis occurs in carriers of HLA-B27 antigen. In some patients, epicleritis is possible in the form of short-term and benign episodes.

Heart damage is a rare manifestation of juvenile ankylosing spondylitis, which occurs in less than 3-5% of patients with juvenile ankylosing spondylitis. Occurs in isolation or as a combination of the following symptoms:

• damage to the proximal aorta, diagnosed only with echocardiography;
• aortic insufficiency;
• atrioventricular blockade of I-II degree.

Very rarely occurs pericarditis.

Kidney damage in patients with juvenile ankylosing spondylitis may be due to several reasons:

• secondary amyloidosis, a rare complication of uncontrolled course of the process in patients with persistent high disease activity;
• IgA-associated nephropathy, observed in 5-12% of patients:
  • is manifested by isolated hematuria or in combination with small proteinuria;
  • develops against a background of high disease activity;
  • high serum IgA;
• side effects of drugs (LS) - NSAIDs or sulfasalazine;
• ascending infection with urogenital reactive arthritis.

The defeat of the axial (axial) skeleton

The defeat of the axial skeleton is a pathognomonic manifestation of juvenile ankylosing spondylitis, the main feature of which, unlike ankylosing spondylitis of adults, is the delayed development of axial symptoms. Juvenile ankylosing spondylitis is characterized by a so-called pre-prescription stage, the duration of which, before the appearance of the first symptoms of spinal cord injury, may be several (sometimes more than 10-15) years. A short pre-presiding stage is possible, and the clinical picture of spondylitis occurs simultaneously with other manifestations if the child falls ill at 12-16 years of age. In young children (up to 5-6 years), the delay between the first symptoms of the disease and the development of a typical clinical picture of juvenile ankylosing spondylitis can be 15 years or more. This revealed regularity suggests that the key pathogenetic mechanisms of the development of ankylosing spondylitis are in close interaction with the physiological processes of growing up, primarily neuroendocrinal or genetic factors that determine them.

The first clinical sign of axial involvement is usually pain in the projection of the sacroiliac joints and the buttock area, manifested as active complaints, and in physical examination. Sometimes the symptoms of sakroileitis are combined with the lesion of the lumbar and lower thoracic or cervical spine. Characteristic for adults, intense, mostly nocturnal, back pain is not typical in childhood. Most often, children have fickle complaints about a feeling of fatigue and tension in the muscles of the back with an inflammatory rhythm, i.e. The emergence in the early morning hours and decreasing after exercise. Sometimes local soreness, limited movement, smoothness of physiological curves of the spine, especially lumbar lordosis, regional muscle malnutrition are revealed. In some patients, these symptoms significantly decrease or completely disappear after adequate treatment, and repeated relapses can occur only after several years.

Clinical symptoms of axial skeletal lesions are confirmed by radiographic signs of sakroileitis and overlying spine. In juvenile ankylosing spondylitis, in contrast to ankylosing spondylitis, adults develop syndesmophytes much less frequently and at much later times, but it is possible to identify the densification of the anterior longitudinal ligament (especially its lateral sections at the level of the lower thoracic segments of the spine) becoming increasingly manifest as the skeleton grows and develops , as well as the progression of spondylitis. Intervertebral joints are affected with the same frequency, as with juvenile ankylosing spondylitis, and with ankylosing spondylitis in adults, but, as a rule, at later stages of the development of the disease. Sometimes the radiologic severity of arthritis of intervertebral joints, for example, in the ankylosis of arcuate articulations in the cervical spine, is greater than the clinical manifestations. Spondylodiscitis can also act as one of the clinical and radiologic signs of spinal lesions inherent in juvenile ankylosing spondylitis.

For the dynamics of the development of the disease with juvenile ankylosing spondylitis is characterized by a distinct dependence on the age of the spectrum of clinical manifestations with a gradual partial regression of some symptoms and the manifestation of others. As the child grows and grows, there is a tendency to a gradual decrease in the frequency and severity of relapses of peripheral arthritis and entesis and, on the contrary, a greater manifestation of lesions of the eyes and axial skeleton. The age-related evolution of the clinical symptoms of the disease leads to a typical clinical picture of ankylosing spondylitis at the age of over 20 years.

A special place among juvenile ankylosing spondylitis is juvenile psoriatic arthritis. Skin psoriasis is not always an obligatory criterion for the diagnosis of juvenile psoriatic arthritis, if a patient traces specific joint manifestations and there is accurate information about the presence of psoriasis in relatives of the first degree of kinship. The appearance of skin lesions and / or lesions of the mucous membranes typical for psoriasis can occur simultaneously with articular syndrome, and in a few years (up to 10-15) after the onset of arthritis. As a rule, there is no parallelism in the timing and severity of peripheral arthritis and skin psoriasis in juvenile psoriatic arthritis.

Juvenile psoriatic arthritis can occur at any age, which, as a rule, determines the characteristics of clinical manifestations of the disease.

• In children under 7 years of age, oligoarthritis is more likely (both lower and upper extremities are affected) in combination with dactylitis.
• In children older than 7 years with a general predominance of oligoarticular variants of the joint syndrome, polyarthritis occurs, up to the destructive mutilating arthritis.
• Relatively rare for children, the spondyloarthritic variant develops almost exclusively in adolescents, it is characterized by the same clinical features as for the entire group of juvenile spondyloarthritis.
• The rare and heaviest mutating variant of juvenile psoriatic arthritis occurs mainly with the early (before 5 years) debut of the disease, various sub-directional subluxations, dislocations, multiple deformations and contractures, especially in the distal limbs. Characteristic articular manifestations of juvenile psoriatic arthritis:
  • arthritis of the distal interphalangeal joint;
  • axial lesion of three joints on one finger;
  • dactylyte;
  • periostitis;
  • intraarticular osteolysis as "pensik - in - cup" ("pencil in a glass");
  • Acoustic osteolysis;
  • mutilating arthritis.

The extra-articular manifestations of juvenile psoriatic arthritis do not differ from those of other spondyloarthritis.

Clinical features of joint damage with enteropathic arthritis (associated with Crohn's disease, ulcerative colitis) are identical to juvenile spondyloarthritis and do not differ in any specificity.

With respect to peripheral arthritis, there is a certain similarity with juvenile spondylitis in two rare pathological conditions associated with cutaneous manifestations and osteitis, chronic recurrent multifocal osteomyelitis and SAPHO syndrome (abbreviation for "S" - synovitis, "A" - aspe conglobata, round deep acne, "R" - pustullosis, "H" - hyperostosis, "O" - osteitis). A distinctive feature of this pathology is multiple lesions of bones of extraarticular localization, especially of the clavicles, pelvic bones, vertebral bodies, etc. In this case, osteomyelitis is aseptic in nature, at any rate, attempts to isolate the pathogen from the lesion are usually unsuccessful.

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