Juvenile Idiopathic Arthritis (JIA)
Nurses, Health Visitors, School Health Advisors and Practice Nurses are often the first contact a child has with health services and are therefore in a prime position to identify early signs and symptoms suggesting arthritis. Early identification of arthritis and access to treatment is key to preventing joint damage and other complications that can occur.
Juvenile Idiopathic Arthritis (JIA) is the umbrella term to describe various subtypes of arthritis. Each subtype differs in terms of clinical features. JIA is defined as arthritis in one or more joints lasting for more than 6 weeks and starts under the age of 16 years.
JIA is the commonest cause of chronic arthritis in children in the UK. In some parts of the world, Lyme disease is much more common. JIA affects 1 in 1,000 children - this is similar to epilepsy in children. There are approximately 12,000 children with JIA in the UK. No laboratory tests, or imaging can ‘prove’ that a child does, or does not, have JIA. The diagnosis of JIA is, therefore, based on the presence and persistence of arthritis and the careful exclusion of any other disease by medical history, physical examination and laboratory tests.
The differential diagnosis for JIA is extensive with conditions ranging from the benign (e.g., hypermobility) to the life threatening (e.g., malignancy, such as leukaemia and solid tumours, infection, non-accidental injury). The presence of any ‘red flags’, such as weight loss, fever, night pain and bone tenderness, suggests infection or malignancy and warrants urgent assessment in secondary care.
The clinical assessment of a child is not the same as that of an adult. The young child may not be able to verbalize pain and the history may be primarily from the parents or carers, or from observations made by teachers and may initially be vague - e.g., 'my child is not quite right' or 'my child is limping'. Examination findings need to be interpreted in the context of normal development.
Clues to suggest inflammatory disease (in joints or muscles):
- Change in behaviour – such as being more irritable, clingy, or reluctant to play.
- Avoidance of activities previously enjoyed (e.g., in play or sport).
- Regression of achieved motor milestones (such as walking or handwriting).
- Morning joint stiffness and pain - the child may be ‘slow to get going in the morning’ or experiences stiffness after periods of rest, such as after long car rides – this is called ‘gelling’.
Untreated, inflammatory arthritis in growing children can interfere with bone growth around the affected joint. For example a child with knee arthritis may have leg length inequality (see photograph below) - this occurs due to increased blood flow causing stimulation of bone growth and increase in length. This may result initially in accelerated growth (causing a longer limb) and then early fusion of the growing parts of the bone (causing ultimately a shortened limb). Similarly abnormal growth of fingers, toes, and the jaw can occur with impact on joint movement and function; use of fingers, problems with walking or getting shoes to fit comfortably or problems with eating and chewing.
The photograph below shows uneven leg length and deformity due to chronic arthritis affecting the left knee and both ankles.