In the diagnosis of Yuha, in addition to the clinical picture described above, specially developed criteria can be used. The most successful are the diagnostic criteria developed by a large group of pediatricians of socialist countries in relation to the diagnosis of juvenile rheumatoid arthritis (1976). Since the term juvenile rheumatoid arthritis at the time was similar to the modern term Yuha, they can be used in the diagnosis of chronic arthritis in children.
When making a diagnosis, you can use the classification proposed by a group of Moscow pediatricians .
According to the proposed classification, the complete diagnosis should look as follows: juvenile chronic arthritis, predominantly articular form (oligoarthritis), seronegative, slowly progressive course, moderate degree of activity, stage II radiological changes, functional deficiency of I degree.
Differential diagnosis. The range of diseases with which UXA is differentiated differs in different forms of the course of the disease.
The most frequent joint variants of the onset rarely cause serious difficulties for differentiation, or these difficulties can be only at the very beginning of the disease. Under real conditions, a differential diagnosis has to be carried out with a group of reactive arthritis, less often with traumatic and metabolic lesions of the joints.
Among the group of reactive arthritis, those closest to UHA are arthritis associated with intestinal infection (yerseniosis, salmonellosis, dysentery), since they are often fairly stable, and intestinal syndrome is very moderate. In these cases, it is necessary to focus on the results of planting stool, serological reactions with the corresponding antigens, diagnosis of ex juvantibus using antibiotics acting on the intestinal group (levomycetin, cephalosporin, etc.). In childhood, it is with these etiological factors that Reuter’s syndrome diagnosis is associated with a typical triad of symptoms.
(arthritis, urethritis, conjunctivitis). The first two of them – arthritis, urethritis, as a rule, the most vivid. Differential diagnosis with rheumatoid arthritis is of greater historical importance due to the fact that with a decrease in the incidence of primary rheumatism and a certain decrease in its activity, cases with marked arthritis are very rare. In such cases, the volatile nature of arthritis, the presence of a heart lesion, a confirmed streptococcal etiology of the disease, allows one to reliably distinguish between rheumatism and YUHA.
Traumatic arthritis is rarely observed in children, and even more rarely are they delayed in their reverse development for a long period. The exception in this regard is traumatic arthritis in hemophilia, but usually the diagnosis of hemophilia is known before the need for differential diagnosis arises.
Exchange arthritis in children is also quite rare and, in actual practice, is observed almost exclusively in obese children. The connection of the pain syndrome with the load on the affected joints, the absence of major changes on the part of the joints makes it possible to quite reliably distinguish this pathology.
There may be difficulties in diagnosing children with mucopolysaccharides, where joint deformities are often noted, the level of the disease, especially in adolescence, and a number of other situations that are more casuistic. Based on the analysis of a large group of patients with JCA and bordering them SOS-being as part of the scientific program with pediatricians of the Soviet Union and the socialist countries at the Department of propaedeutics of children: disease developed by computing a table of differential diagnosis of JCA and arthritis of other genesis .
In the presented table, the signs are arranged in the order of their informativeness. The rules for working with the table are as follows: an algebraic summation of the diagnostic coefficients is performed items, starting with the most informative. The diagnostic procedure continues until the threshold values are reached, after which the further summation of the coefficients ends (for this table, the threshold coefficients were –j – 6.0 and –2.0). Thus, upon reaching the sum of + 6, 0, we can talk about the presence of juvenile chronic arthritis in the child, with a sum of –2.0 arthritis of a different genesis. In the case when the sum of all the signs listed in the table does not reach one of the threshold values, the diagnosis is considered uncertain and additional studies are needed for the final diagnosis. The absence of individual signs (for example, biopsy of the synovial membrane) does not exclude work with the table, but reduces the reliability of the results. Using the table gives the correct answer in 95% and incorrect in 1% of cases,in other cases, the answer is. undefined.
In the systemic onset of UXA, differential diagnosis has to be carried out with some generalized infectious processes, in particular, streptococcal and yersenic infections and the onset of some diffuse connective tissue diseases, of which
first place are systemic lupus erythematosus and nodular peri-. arteritis, less often dermatomyositis. Until the articular syndrome takes on its typical character for YUHA — stability, aggravation, and effusion in the joint cavity — a reliable differential diagnosis is very difficult. However, in most cases by the three months since the onset of the disease, the period that is considered mandatory for the diagnosis of YUHA, the diagnosis becomes clear.
A somewhat different plan of difficulty is faced by a doctor when trying to distinguish between forms of UHA depending on the immunopathogenesis, and under these conditions special immunological studies are of great importance. The most important are the methods that allow to state the activation of various immunity links and, on the contrary, reveal the presence of a constitutional or induced immunological deficit. However, not all of the existing methods can currently be used in the clinic, since many are not available to methodologically conventional laboratories or have not gone beyond the experiment. According to the literature and on the basis of our own experience from the immunological tests for assessing cellular and humoral immunity, the following can be recommended for screening the examination of a patient with YUHA: 1. Rheumatoid factor (RF). When YUHA can be identified as classic 19S IgM — RF, overt and covert, as well as IgG—, IgA — RF. Of greatest interest is the IgM — RF, which is identified by the usual two methods – the Waaler – Rose reaction and the latex test. Serum positive forms of Yuha are especially frequent in girls over 10 years of age with a polyarthritic onset. This form resembles an adult type of early-onset RA. As in adults, severe damage to the joints with early destruction, rheumatoid nodules, and associations cHLA — DR4. Seronegative forms of the polyarthritic principle differ in their clinical and evolutionary features; begin at the age of 2–5 years, progress slowly, have a smaller number of affected joints with moderate or no destruction, the best functional prognosis.