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ABOUT CHILDHOOD RHEUMATOLOGICAL DISORDERS

JUVENILE IDIOPATHIC ARTHRITIS

What is it?
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Juvenile idiopathic arthritis (JIA) is a chronic disease characterized by persistent joint inflammation; the typical signs of joint inflammation are pain, swelling and limitation of movement. “Idiopathic” means that we don’t know the cause of the disease and “juvenile”, in this case, means that symptoms appear before 16 years of age.

What does chronic disease mean?

A disease is said to be chronic when the appropriate treatment does not lead to an immediate recovery, but only to an improvement of symptoms and laboratory test results. This also means that when the diagnosis is made, it is impossible to say for how long the child is going to be sick.

How frequent is it?
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JIA is a rare disease that affects about 80-90 per 100,000 children.

What are the causes of the disease?

Our immune system protects us from infections (virus and bacteria). In doing so, it is able to distinguish what is harmless and part of our body and what is foreign and potentially dangerous, which it destroys.

It is believed that chronic arthritis is a consequence of an abnormal response of our immune system, which, due to unknown causes, loses part of its capacity to distinguish between dangerous and normal cells and attacks its own joint components. For this reason, diseases such as JIA are called auto-immune, meaning that the immune system reacts against the organs of its own body. However, the precise mechanisms that cause JIA, as with as most human chronic inflammatory diseases, are unknown.

What happens to the joints?
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The synovial membrane is the cellular lining surrounding the joint and is usually very thin. In JIA it becomes much thicker and filled with inflammatory cells, while the amount of the synovial fluid inside it increases. This causes swelling, pain and limitation of movement. A characteristic feature of joint inflammation is joint stiffness, which occurs after prolonged rest. It is, therefore, particularly pronounced in the morning (and referred to as morning stiffness).

Often the child attempts to reduce pain by keeping the joint in a position half-way between flexion (fully bent) and extension (straight), this position is called antalgic indicating the fact that it is maintained to reduce pain. If not properly treated, joint inflammation may produce damage by two main mechanisms:

  1. The synovial membrane may get very thick and form what is called the synovial pannus, which, through the release of various substances, provokes the erosion of articular cartilage and bone.
  2. Keeping the joint in the antalgic position for a long time causes muscle atrophy, which is the wasting away of muscles and soft tissues, leading to flexion deformity.

Will the child have a normal adult life?

This is one of the main goals of therapy and it can be reached in the majority of cases. Therapy for JIA has improved dramatically in the last ten years and it is conceivable that several new drugs will be available in the near future. The combined use of pharmacological treatment and rehabilitation prevents joint damage in the majority of patients.

Major attention should also be paid to the psychological impact of the disease on the child and his family. A chronic disease like JIA is a difficult challenge for the whole family and of course, the more serious the disease, the harder it is to cope with it. It will be difficult for the child to cope properly with his disease if the parents don’t. The parents may develop a strong attachment towards their sick child and, in order to prevent him from any possible problem, can become-overprotective. A positive attitude from parents to support and encourage the child to be as independent as possible, despite the disease, is extremely valuable in helping the child to overcome difficulties, to successfully cope with his peers, and to develop an independent, well-balance personality.

A pediatric rheumatology team should offer psychosocial support to the child and family when needed.

SYSTEMIC LUPUS ERYTHEMATOSUS

What is it?
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Systemic lupus erythematosus (SLE) is a chronic autoimmune disease (meaning that the immune system attacks the body instead of viruses and bacteria). It can affect various organs of the body, especially the skin, joints, blood and kidneys. SLE is a chronic disease, which means that it can last for a long time.

The name systemic lupus erythematosus dates back to the early 20th century. Systemic means affecting many organs of the body. The word lupus is derived from the Latin word for wolf, and refers to the characteristic butterfly like rash on the face, which reminded doctors of the white markings present on a wolf’s face. Erythematosus in Greek means red, and refers to the redness of the skin rash.

How common is it?

SLE is a rare disease that affects about five in a million children per year. Onset of SLE is rare before five years of age and uncommon before adolescence. Women of childbearing age (15 to 45) are most commonly affected and, in that particular age group, the ratio of affected females to males is nine to one. In younger children, before puberty, the proportion of affected males is higher.

SLE is recognized worldwide. The disease appears to be more common in children of African American, Hispanic, Asian, and Native American origin.

What are the causes of the disease?
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The exact causes of SLE are not known. What is known is that SLE is an autoimmune disease, where the immune system loses its ability to tell the difference between a foreign intruder and a person’s own tissues and cells. The immune system makes a mistake and produces autoantibodies that identify the person’s own normal cells as foreign, and eliminates them. The result is an autoimmune reaction, which causes the inflammation that affects specific organs (joints, kidneys, skin, etc).

Inflammation means that the affected body parts become hot, red, swollen and sometimes tender. If the signs of inflammation are long lasting, as they can be in SLE, then damage to the tissues can occur and normal function is impaired. This is why the treatment of SLE is aimed at reducing the inflammation.

Multiple inherited risk factors, combined with random environmental factors, are thought to be responsible for the abnormal immune response. It is known that SLE can be triggered by a number of factors, including hormonal imbalance at puberty, environmental factors, viral infections and certain medications

What is the long-term prognosis (predicted course) of the disease?

The outcome of SLE improves dramatically with the early and judicious use of glucocorticosteroids and immunosuppressive agents. Many patients with childhood onset SLE will do very well. Nonetheless, the disease can be severe and life threatening and may remain active throughout adolescence and into adulthood.

The prognosis for SLE in childhood depends on the severity of internal organ involvement. Children with significant kidney or central nervous system disease require aggressive treatment. In contrast, mild rash and arthritis may be easily controlled. The prognosis for an individual child, however, is relatively unpredictable.

Can it be treated/cured?

At present there is no cure for SLE, but the vast majority of children with SLE can be treated successfully. The treatment is aimed at preventing complications, as well as treating the symptoms and signs of the disease.

When SLE is first diagnosed it is usually very active. At this stage it may require high doses of medication to control the disease and prevent organ damage. In many children, the treatment brings SLE flares under control and the disease may go into remission when little or no treatment is needed.

How long should treatment last for?

The treatment should last as long as the disease persists. It is generally agreed that most children with SLE are withdrawn completely from glucocorticosteroid drugs, only with great difficulty, during the initial years after diagnosis. Even long-term, very low dose, maintenance glucocorticosteroid therapy can minimize the tendency toward flares and keep the disease under control. For many patients, it may be best to maintain a low dose of glucocorticosteroids rather than risk a flare.

SCLERODERMA

What is it?
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Scleroderma is a Greek word that can be translated as “hard skin”. In this disease, the skin becomes shiny and hard. There are a wide variety of diseases in which skin hardening is the most prominent feature and there are two different types of Scleroderma, localized and systemic scleroderma.

In localized scleroderma the disease is limited to skin and the tissues located under the affected skin. It can be in patches (morphea), or occur as a tight band (linear scleroderma). In systemic scleroderma (or systemic sclerosis) the process is widespread and involves not only the skin, but also the internal organs of the body. This can lead to different symptoms, including heartburn, difficulty in breathing, and high blood pressure.

How common is it?

Scleroderma is a rare disease. Estimations of its frequency never exceed three new cases in 100,000 children every year. Localized scleroderma is the most common form in children and predominantly affects girls. Only about 10%, or less, of all scleroderma in children are systemic sclerosis.

What are the causes of the scleroderma?

Scleroderma is an inflammatory disease, but the reason for the inflammation has not yet been discovered. It is probably an autoimmune disease, which means that the immune system of the child reacts against itself. The inflammation causes swelling, heat, and the production of too much fibrous tissue.

What is the long-term prognosis of the disease?

Morphea usually leaves only cosmetic skin defects. Linear scleroderma can leave the affected child with severe problems due to loss of muscle and decreased bone growth, as well as causing stiff and deformed joints. Systemic sclerosis is potentially a life-threatening disease. The degree of internal organ involvement (cardiac, renal and pulmonary system) varies among patients and is the major determinant of long-term prognosis. The disease may stabilize, in some patients, for long periods of time.

Is it possible to recover completely?

Children with localized scleroderma recover. After some time, even the hard skin may soften and appear normal. Recovery from systemic sclerosis is much less probable, but significant improvements, or at least disease stabilization, may be achieved.

JUVENILE SPONDYLOARTHROPATHIES

What is it?

The juvenile spondyloarthropathies constitute are a group of chronic inflammatory diseases of the joints (arthritis) and tendon attachments to certain bones (enthesitis) affecting, predominantly, the lower limbs and, in some cases, the pelvic and spinal joints (sacroliitis - buttock pain and spondolytis - lower back pain).

In some cases, the onset of symptoms is triggered by enteric (gastro-intestinal) or urogenital bacterial infections (reactive arthritis). Juvenile spondyloarthropathies are significantly more common in people carrying HLA-B27, a genetic marker, which predispose individuals to this disease, although why this is the case is not fully understood, as yet.

The prevalence of some clinical features at onset and severity throughout the course of the disease, differ in the childhood form to those of adults, but may still resemble adult onset spondyloarthropathies. Patients with juvenile idiopathic arthritis, classified into the enthesitis related arthritis group (see JIA information), are included in the group of juvenile spondyloarthropathies.

What diseases are called juvenile spondyloarthropathies?

Despite some controversy, juvenile spondyloarthropathies include the same diseases belonging to the group of adult spondyloarthropathies, including ankylosing spondylitis, reactive arthritis (and Reiter’s syndrome), psoriatic arthritis (of the spondyloarthropathy type), and arthritis associated with inflammatory bowel disease (of the spondyloarthropathy type). Some children, not fulfilling diagnostic criteria for the disease enlisted above, may have the so-called undifferentiatied spondyloarthropathy.

Other conditions, specifically the seronegative enthesopathy and arthropathy (SEA) syndrome and enthesitis related arthritis refer to juvenile spondyloarthropathies.

Can it be prevented?

Prevention is not possible since the causes of the disease are unknown. It is not useful to test other siblings for the HLA-B27 if they do not have any symptoms that can be linked to a spondyloarthropathy

Can it be treated or cured?

There is no curative treatment since the cause of spondyloarthropathies is unknown. However, therapy can be very useful to control disease and prevent damage.

Will the child have a normal adult life?

This is one of the main goals of the therapy and it can be reached in the majority of cases. Therapies for these kinds of diseases in childhood have improved dramatically in the last ten years. The combined use of pharmacological treatments and rehabilitation is now able to prevent joint damage in the majority of patients. Yet in patients with chronic disease, joint damage may be important and can limit the patient’s daily life and professional ambitions.

RHEUMATIC FEVER AND POST-STREPTOCOCCAL REACTIVE ARTHRITIS

What is it?
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Rheumatic fever has been defined as a disease triggered by infection caused by streptococcus. The disease may cause permanent damage to the heart, and presents itself by transient arthritis, carditis, or a movement disorder called chorea, in addition to skin rashes or skin nodules.

How common is it?

In the past, epidemics of rheumatic fever and localized outbreaks in communities have provided the background to suggest it is triggered by infection, before antibiotics became available. A dramatic incidence decline was seen worldwide after the widespread use of penicillin for treatment of pharyngitis. It most commonly occurs between the ages of 5-15, with peak incidence around eight. In developing countries, it remains a challenge as the leading cause of heart disease disability amongst young people, with recurrent attacks more likely to increase heart damage.

During the eighties however, a resurgence in outbreaks was reported in areas, in what would otherwise be considered low-risk populations. It is included among the many rheumatic diseases of children and adolescents, because of its joint manifestations.

What are the causes of the disease?

The disease is the consequence of an abnormal immune response to throat infection with streptococcus in genetically predisposed individuals. This means that the immune system attacks, not only the streptococcus, but also normal body tissue. The time lapse between the infection and disease onset is very variable.

This unique relation to infection provides the basis for treatment and prevention. Streptococcal throat infection is common in the general population, although only a small minority of patients will develop the disease. The risk increases in patients with a previous flare, mostly three years after the onset of disease.

POST-STREPTOCOCCAL ARTHRITIS

What is it?

In adults and youngsters, cases of streptococcal associated arthritis are described that do not fulfill the criteria of acute rheumatic fever. Arthritis develops in the earlier phase of the disease and may involve joints of the hands. It responds poorly to anti-inflammatory treatment and, usually, lasts for months. These features resemble other forms of arthritis. The diagnosis relies on clinical findings, in association with evidence of recent streptococcal infection.

Some of these patients have been shown to develop carditis later on. Most doctors agree that post-streptococcal arthritis is a variant of rheumatic fever, therefore, antibiotic prevention is recommended, as well as heart evaluation checking for carditis.

JUVENILE DERMATOMYOSITIS

What kind of disease is it?
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Juvenile dermatomyositis (JDM) belongs to a group of diseases called autoimmune diseases. In autoimmune diseases an abnormal reaction of the immune system causes an inflammation in body tissues when no infection is present. In dermatomyositis, the inflammation is in very small blood vessels in muscle (myositis) and skin (dermatitis). This leads to characteristic symptoms, such as muscle weakness, or pain, mainly in the muscles surrounding the hip and shoulder girdle, and skin eruptions in the face, above the eyelids, on the knuckles, knees and elbows.

The disease can be present in children and in adults. If the symptoms of dermatomyositis present before the age of 16 years, the disease is addressed as the juvenile form.

How common is it?

JDM is a rare disease in children. The incidence of JDM is estimated to be around four in 100,000 children. Girls are affected twice as often as boys. Onset is most common between the ages of four and 10 years. There is very little evidence for any geographically or racially linked predisposition to JDM.

Dermatomyositis is also seen in adults, but the presentation and course of the disease differs from the juvenile form of dermatomyositis. Unlike in adults, there is no association with the development of malignancy.

What are the causes of the disease and is it inherited?
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As in most autoimmune diseases, the exact cause of dermatomyositis is not yet known. The origin of the disease is probably multifactorial, which means that a combination of genetic and environmental factors leads to an increased susceptibility to dermatomyositis. JDM, therefore, is not an inherited disease. At most, there is an increased frequency of autoimmune disease in families of children with JDM.

As for the environmental factors associated with the development of JDM, a lot of investigations have been performed. It is hypothesized that microorganisms might trigger an abnormal response within the immune system in autoimmune diseases.

Prognosis

If the disease is controllable, the overall prognosis of JDM is favorable. In contrast to adults with DM, JDM is not associated with the occurrence of a malignancy. However, there is a mortality risk in those rare cases where respiratory, cardiac, neurological, or gastrointestinal complications develop during the acute phase of the disease. Functional outcome is largely determined by the development and extent of calcium deposits (called calcinosis) and the severity of muscle involvement, which can lead to muscle atrophy and contracture. Calcinosis is said to occur in 10 to 30% of all JDM children. There is no proven therapy for calcinosis.

The course of the disease can be divided into several subtypes. JDM, with a monocylic course, is defined as just one episode of disease that is in remission within two years of onset, without relapses. This form has the most favorable prognosis.

JDM, with a chronic polycyclic course, is characterized by prolonged remission with one or more relapses after stopping treatment.

Chronic, active disease, is characterized by a chronically persistent disease activity despite treatment (chronic remittent disease course). This last group has a higher risk of complications.