Ankylosing spondylitis (AS) is a particular type of arthritis. It particularly affects the joints of the spine and sacroiliac linking the pelvis (hip bone) to the column. This disease often also affect other joints such as knees, ankles, toes, hips and rib cage. When it begins before the age of seventeen is called Juvenile Ankylosing spondylitis (JAS).
The EAJ and diseases linked to it are rare but constitute a significant proportion of all young people with chronic arthritis. The EAJ can occur in 1 in 1,000 children, and appears much more frequently in boys than in girls. It usually starts in puberty or adolescence.
The cause of the EAJ is unknown. However, it is known that children who inherit a gene called HLA B27 on one or both parents are more likely to develop the disease than children who do not. Furthermore, the EAJ is rare in white children have the gene HLA B27 (approximately 8% of the normal population has this gene). In addition, the B27 does not cause disease itself. It is believed that bacterial infection of the intestinal tract or the genito-urinary tract may trigger the onset of AD.
SYMPTOMS OF THE DISEASE
In children, the EA usually begins in the ankle, knee or hip. Some months or years later, other joints may be involved, particularly those of the spine or sacroiliac. The disease behaves differently in each person.
The first symptom may be the enthesitis EAJ, a painful inflammation of tendons and ligaments at the site where they attach to bone, usually near or around the joints. The pain is usually in the joint (as in rheumatoid arthritis) but with a joint. In children, this type of pain occurs most often under or behind the heel below the toes or around the kneecap.
About one fifth of patients develop EAJ eye inflammation called iridocyclitis or uveitis. Can occur in one or both eyes, and usually accompanied by acute eye redness, sensitivity to sunlight and pain. Other complications (which can affect the heart, kidneys or spinal cord) are very rare.
Topical corticosteroids can be used to treat eye inflammation. Surgery usually is not required, but in a few cases of severe joint destruction may necessitate hip replacement.
THE DIAGNOSIS OF EAJ
The diagnosis of the EAJ is made on the basis of clinical history, physical characteristics of joint inflammation and tissue and the results of certain laboratory and radiological examinations. Experienced doctors in the care of children with JAS will make a careful assessment of arthritis; ask carefully about enthesitis and look at the physical examination, spinal mobility tested, sacroiliac pain and chest movement with breathing. There is no specific laboratory test for EAJ, but tests can be very useful. Blood tests showed that children with EAJ not have rheumatoid factor or antinuclear antibodies, which are common in other types of juvenile chronic arthritis. The genetic marker HLA B27 is not an anomaly in itself, but its presence correlates with the development of EAJ in a child with arthritis. This means that the test for HLA B27 is an important test, but diagnosing EAJ.
Radiographs of the sacroiliac joints, which must show changes to make a clear diagnosis of AD in adults, may be normal in children with JAS, or show those changes over time, when the individual is an adult. Keep in mind that the plates of the sacroiliac joints are usually difficult to interpret in younger kids because bones are growing along the joint.
The EAJ can resemble other diseases, and physicians should be careful to make a proper diagnosis. There are several diseases associated with AD who have other problems besides arthritis. These include: Crohn's Disease, ulcerative colitis (inflammation of the intestines), Reiter syndrome (arthritis with inflammation of the eyes and loose lower urinary tract infection), psoriasis. All of these can occur in children.
THE TREATMENT OF EAJ
The treatment of children with JAS is individualized according to the specific problems of each patient, depending on how severe are the disease and its complications. This treatment is performed, ideally, with the help of a multidisciplinary team which can achieve combine individual efforts to benefit the patient. Its members are: pediatric rheumatologist (doctor with highly specialized training and experience in caring for children with rheumatic diseases such as EAJ) physical therapist (the professional responsible for developing appropriate exercise programs for children with JAS, to be carried out in the gym and at home, with the goal of rehabilitating the patient), occupational therapist (which will ensure that the child can physically perform well in school, p adapt elements to it, and get to live as independently as possible) psychologist, nutritionist, ophthalmologist, orthopedist and other doctors who can become involved the treatment of youth.