Juvenile arthritis; a little ache can mean a lot

Dedication: The little dancer. Thank you for helping me learn.

July is Juvenile Arthritis Awareness Month. A rare but serious form of childhood joint disease, juvenile idiopathic arthritis (JIA) disease may attack and isolate children at pivotal times in their emotional, social and school development. Overall prevalance is around up to 0.1% of children, with girls affected more than boys. Diagnosis is confirmed if a child under 16 has more than six weeks of joint pain, without any other known cause.

What causes JIA?

The mechanism of disease is thought to be autoimmune. Our 'defence cells' label harmless tissues, signalling them for destruction. It may be that genetics, viruses or other factors play a role in confusing the body's system. This internal war wreaks havoc on the joint and sometimes the body as a whole. This process tends to come in waves. Different chemical markers can be used to distinguish between types of JIA.

The two types of JIA

In fact, there are many types of this disease. For the case of simplicity, we can subdivide JIA into 'joint predominant' and 'systemic onset' disease. The difference between the two is that the latter tends to effect the body as a whole. Symptoms may overlap. Specific chemical markers will not be discussed, as they are often mixed and only useful in expert hands.

What are the symptoms of JIA?

Symptoms of joint disease include pain, stiffness and swelling. Fever may or may not be present. Very few joints may be affected, but in more severe or 'seropositive' (rheumatoid) forms, we may see many joints involved on both sides of the body. Attacks may come and go over periods of weeks to months. These 'flares' may resolve but some may progress and cause 'chronic' (long term) symptoms due to joint damage. Deformity and growth restriction may occur dependent on age and severity.

Systemic features tend to include rash, lymph node (gland) swelling, fever, tiredness and tummy or chest pain. The fever may peak in the mornings and evenings, and can be above 39 degrees at its highest. Small swellings may occur on the joints (rheumatoid nodules).

There is a crossover between systemic and seropositive disease, where symptoms may be shared. Inflammation in the eyes (uveitis) is possible in some forms and requires urgent attention. In rare cases this disease may prompt a rapid and severe reaction in the body, leading to diffuse bleeding, which requires urgent and intensive hospital care.

What treatments options are there?

Investigation may include X-rays and blood tests. Basic treatment includes painkillers, and a range of immunosuppressant drugs designed to dampen our 'defence cells'. These drugs may include steroids, such as those used in asthma, but extend to more complex drugs that act on the replication apparatus of the cells themselves. These drugs are known as 'biologics' and often have nasty side effects, so are only used under expert care.

General prognosis and research

Overall prognosis is variable, but with early diagnosis and targeted treatment using drugs, physiotherapy and counselling, patients' outcomes are improved. A significant proportion of children will have long- term pain, with or without deformity. Systemic and seropositive disease is more likely to recur or become chronic. Long-term treatments may include surgical management of troublesome joints. Osteoporosis and other effects of long-term steroid use may evolve.

Research into the development, diagnosis and treatment of these diseases is ongoing. Severe disease can have a significant lifelong impact on the young, both physical and psychological.

Many of you may know a child with joint disease and can attest to its burden. If you wish to find out more and help the effort, please Arthritis Research UK.


Ben is a young NHS doctor in the Southwest. His interests include neurology, health communication, and medical ethics. He is also an avid advocate of compassionate care and quality improvement, running a project in the Southwest around medical humanities. Please follow and support: Dr Janaway on Facebook Dr Janaway on Twitter

The opinions expressed in this article are the author's alone and do not reflect those of the NHS or associated agencies. All facts are based on the best available evidence. The author is happy to receive questions. There are no conflicts of interest and due consideration has been given to the consequence of conclusion or interpretation.

Sources:

1) Simon, C, Everitt H 'The Oxford Handbook of General Practice' 4th Ed 2016, Oxford

2) http://emedicine.medscape.com/article/1007276-workup

3) www.the-rheumatologist.org/article/macrophage-activation-syndrome/

4) http://www.arthritis.org/about-arthritis/types/juvenile-arthritis/

5) http://www.jia.org.uk/

6) http://www.webmd.com/rheumatoid-arthritis/features/autoimmune-disease-and-ra

7) http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3012272/

8) http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3490766/