Arthritis means inflammation of the joint, which usually results in pain, stiffness and swelling. There are many causes of joint pain in children. However, most of these are not arthritis. There are many different forms of arthritis affecting children, some of which have specific names (listed below.) Occasionally, it is not possible to give a particular name to a form of arthritis in a child.

Systemic arthritis - arthritis with fever and rash, beginning in children of younger age particularly. The child may be quite unwell before arthritis becomes obvious. Other features, including swelling of the lymph glands in the neck, under the arms and groin, may begin before diagnosis of Systemic Arthritis. Rarely, the lining of the heart or lungs may become inflamed (pericarditis or pleuritis respectively.) Some children with systemic arthritis may have problems with swollen, painful joints for many years, even into adulthood.

Polyarthritis - arthritis affecting many joints, particularly in girls. This form of arthritis may begin in the early childhood years when it affects the fingers and toes as well as larger joints. It is also associated with 'silent' eye disease.

In teenage girls, a different form of polyarthritis similar to adult 'rheumatoid arthritis' can be identified using blood tests for 'rheumatoid factor.' However, in most children, blood tests cannot be used to diagnose arthritis. Many patients with polyarthritis may continue to have joint problems in their adult years.

Oligoarthritis - arthritis affecting only a few joints (four or less) is the commonest form of arthritis in children. It affects young children, particularly girls, and is associated with an eye disease (chronic iridocyclitis). The eye disease can only be detected by 'slit lamp' examination of the eyes, which should be done every few months. Many children with oligoarthritis improve after some time, but if a few joints remain swollen, the disease is termed persistent oligoarthritis. If the disease worsens, and more joints become involved, it is called extended oligoarthritis.

Enthesitis-related arthritis - arthritis which usually begins in older boys or teenagers. It may also cause painful areas in the soles of the feet or other areas around the knees or hips where the ligaments attach to the bone. This form of arthritis is associated with a genetic factor (HLA-B27). Eventually the spine may become stiff and painful, and in adults this is known as ankylosing spondylitis.

Psoriatic arthritis - arthritis with the typical skin rash of psoriasis (see Psoriatic Arthropathy). Even if the rash is absent, psoriatic arthritis can be diagnosed by other features, such as 'finger-nail pitting' or even a family history of psoriasis. Children with this form of arthritis should also be checked regularly for eye inflammation by an ophthalmologist using a slit lamp.

Inheritance patterns
It is very rare to have more than one child with arthritis in one family, but there are some genetic factors passed on through the generations that may make it more likely that a child will develop arthritis. The role of the environment, e.g. bacterial or viral infections, in triggering off the disease is being questioned.

Prenatal diagnosis
None.

Medical test written February 1999 by Professor T Southwood. Last updated January 2004 by Professor T Southwood, Professor of Paediatric Rheumatology, University of Birmingham, Birmingham, UK.

CHILDREN'S CHRONIC ARTHRITIS ASSOCIATION

Children's Chronic Arthritis Association
Ground Floor Office
Amber Gate
City Walls Road
Worcester
WR1 2AH
Tel: 01905 745595 (Mon-Fri, 10am-1pm)
Fax: 01905 745703
e-mail: info@ccaa.org.uk
Web: http://www.ccaa.org.uk

The Association is a National Registered Charity No. 1004200, established in 1988. It offers support by telephone, letter and e-mail for families of affected children and can offer area family contacts. It publishes a bi-annual newsletter and produces information booklets, details on request. Every year it organises a family educational and activity weekend. The Association has approximately 2,000 members.

Group details last confirmed August 2007.

THE LADY HOARE TRUST

The Trust, which has offered support, practical help and financial assistance for children with arthritis, limb disabilities and rare syndromes not covered by other organisations, merged with Contact a Family on 1st December 2004. For more details of the services offered please call the Contact a Family Helpline, Tel: 0808 808 3555.

Group details last updated December 2004.

Choices
PO Box 58
Hove BN3 5WN
Tel: 01273 430219
e-mail: info@kidswitharthritis.org
Web: http://www.kidsunlimited.info for children and teenagers with Arthritis
Web: http://www.kidswitharthritis.org

Choices is a National Registered Charity No. 1093971, established in 2001. It provides a wealth of information including a free comprehensive handbook for families of children with arthritis via the website and by phone, e-mail and letter. It is able to offer advice and work with families to ensure they receive services appropriate to their child's needs. Choices can also provide information and training for professionals working with affected families. The Choices handbook is also published in a Welsh edition. The web site for children and teenagers with arthritis is produced by children and teenagers.

Group details last confirmed October 2007.

Support is also available from Arthritis Care (see entry, Arthritis (Adult)).