2024-02-15 13:26:50
Aysor.am continues the series of publications dedicated to Juvenile Idiopathic Arthritis. By following this series, you will get to know the causes of this disease, symptoms, different forms of manifestation, types of the disease, features of treatment and care.
There are different types of Juvenile Idiopathic Arthritis (JIA). They are mainly distinguished by the number of affected joints (oligoarticular and polyarticular IIA), as well as by the presence of additional signs, such as fever, rash, etc.
The diagnosis of different types is made on the basis of the control of symptoms during the first 6 months of the disease, therefore they are often called the initial forms of the disease.
Systematic IIA
“Systemic” means that, in addition to the arthritis, various internal organs can be affected. Systemic IIA is characterized by the presence of fever, rash, inflammation of various body organs, which can be expressed before arthritis or during the presence of arthritis. There is a fever and a rash, which is mainly expressed during the maximum increase in body temperature. Other signs include muscle pain, enlarged liver, spleen, lymph nodes, and inflammation of the membranes surrounding the heart and lungs (pericarditis and pleurisy).
Arthritis (usually 5 or more joints are affected) can occur early or later in the disease. Girls and boys of different ages are affected by this disease, but it is most often found early and
in preschool children.
In about half of patients, the fever and arthritis last for a limited time; in these patients, as
As a rule, the long-term prognosis is more favorable. In another part the fever tends to decrease, but at the same time the arthritis increases and is sometimes difficult to treat. In a minority of patients, fever and arthritis coexist. Systemic IA accounts for less than 10% of all IA; it is characteristically childish
in adulthood and rarely occurs in adults.
Polyarticular IIA
Polyarticular JIA is characterized by involvement of 5 or more joints during the first 6 months of the disease and the absence of fever. The determination of rheumatoid factor in the blood allows to distinguish 2 forms of YIA polyarthritis: RG positive and
RG negative.
RG positive YIA polyarthritis very rare in children (less than 5% of all IIA patients). It is the adult equivalent of RA-positive rheumatoid arthritis (the most common type of chronic arthritis in adults). In this type of arthritis, the arthritis is symmetric, primarily the small joints of the hands and feet are affected, later other joints are involved. It is more common in females than males and usually begins after the child is 10 years old. This disease often has a severe course.
RG negative YIA polyarthritis makes up 15-20% of all IIAs. It can occur in children of all ages. Any joint can be affected. both large and small joints are usually affected. In both forms, treatment should be started early, soon after diagnosis. Early and adequate treatment is believed to give better results. In any case, it is difficult to predict the outcome of treatment in the early stages of the disease. It varies greatly from child to child.
Oligoarticular IIA (stable or diffuse)
Oligoarticular IIA is the most common subtype of IIA, accounting for about 50% of all cases. This disease is characterized by the involvement of less than 5 joints during the first 6 months and the absence of systemic signs. In this case, large joints (such as the knee and ankle joints) are affected asymmetrically. Sometimes only one joint is affected (monoarticular form). In some patients, the number of affected joints increases to 5 or more after the first 6 months. This is called oligoarthritis proliferative. If the number of affected joints remains up to 5 throughout the disease, this type is called stable oligoarthritis. Oligoarthritis usually begins before the age of 6 and is more common in girls. With timely and correctly selected treatment, the prognosis is often good, especially if only a few joints are affected. If new joints are involved and polyarthritis develops, the prognosis is different.
A significant proportion of patients may develop eye complications, such as inflammation of the anterior part of the eyeball, the blood-vessel-rich membrane that surrounds the eye (anterior uveitis). Because of the membrane of the eye
the anterior part is composed of the iris and ciliary body, the complication is called either iridocyclitis or anterior chronic uveitis. In JIA, this lesion develops invisibly without causing any obvious signs (pain or redness). If left undiagnosed or untreated, anterior uveitis can progress and lead to serious eye damage. Therefore, early detection of this complication is very important. Because the eyes do not turn red and the child does not complain of decreased vision, anterior uveitis may not be noticed by the parents or the doctor. Early onset of IIA and presence of ANA (anticortical antibodies) are risk factors for developing uveitis.
For high-risk children, regular eye exams with a special instrument called a slit lamp are critical. The frequency of the ophthalmologist’s examination is usually once every 3 months and should continue for a long time.
Psoriatic arthritis
Psoriatic arthritis is characterized by arthritis combined with psoriasis. Psoriasis is an inflammatory skin disease with scaly patches on the skin, often located on the elbows and knees. Sometimes only the nails are affected or there is a family history of psoriasis. A skin lesion may precede or
follow the onset of arthritis. Typical signs of this subtype of YIA include hand and foot
complete swelling of the fingers (so-called sausage fingers or dactylitis) and changes in the nail (porosity). First-degree relatives (parents, siblings) may also have psoriasis. Chronic anterior uveitis can also develop in this case, so regular eye examinations are recommended. The outcome of the disease varies, as the skin and joints respond differently to treatment. If the child has arthritis in fewer than 5 joints, the treatment is the same as for the oligoarticular form. If the child has more than 5 affected joints, the treatment is the same as for the polyarticular form. The difference may be related to the response to treatment for both arthritis and psoriasis.
Enthesitis combined arthritis
In this arthritis, the large joints of the lower limbs are most often affected, and enthesitis develops. enthesitis means inflammation of an “enthesis” where a tendon attaches to a bone (an example of an enthesis is the heel). Located in this region
inflammation is usually associated with severe pain. The most common enthesitis is located on the soles and back surface of the heels, where the Achilles tendons attach. Sometimes these patients develop acute anterior uveitis. Unlike other forms of IIA, this usually causes red and watery eyes (watery eyes) and sensitivity to light. Many patients have a positive laboratory test called HLA B27, which suggests a family predisposition to the disease. This form mostly affects boys, and it usually starts before the age of 6. The course of this form of the disease is different.
in some joints, the disease eases over time, while in others, it spreads to the lower parts of the spine and pelvic joints, sacroiliac joints, which leads to limitation of spinal flexion. Morning pain in the lower parts of the back, accompanied by cramping, is very typical of inflammation of the spinal joints. This form resembles a disease of the spine that occurs in adults and is called
ankylosing spondyloarthritis.
What are the causes of chronic iridocyclitis? Is it related to arthritis?
Inflammation of the eye (iridocyclitis) is caused by an abnormal immune system response to the eyes
(autoimmune). However, the exact mechanisms are not known. This complication is mainly observed with early onset of IIA and
in patients with a positive ANA. Factors linking the eye to joint disease are unknown.
However, it is important to remember that arthritis and iridocyclitis have independent processes, and regular slit-lamp examinations should be continued even if the arthritis is improving, as eye inflammation can occur without symptoms and even when the joint condition is better. : The course of iridocyclitis is characterized by periodic exacerbations, which does not depend on exacerbations of arthritis. Iridocyclitis usually follows arthritis or
occurs at the same time as arthritis. Less commonly, it precedes arthritis. These cases usually
are the most unfavorable. since the disease is asymptomatic, late diagnosis can cause visual impairment
to be
Is this disease different in children and adults?
For the most part, yes. RG-positive polyarthritis, which accounts for approximately 70% of adult rheumatoid arthritis, accounts for only 5% of IIA. Early-onset oligoarthritis accounts for 50% of all forms of IIA, but does not occur in adults. Systemic arthritis is common in children and is rarely seen in adults.
Follow our future publications, where you will get to know the different forms of treatment and features of care for Juvenile Idiopathic Arthritis.
If you notice an error or bug in the text, send a message to the editor by specifying the error and then pressing Ctrl-Enter.