Question: What is the youngest age a child has developed arthritis? And why do you think that is?

Sarah Clarke answered on 2 Mar 2020:

Hi. Thanks for your question! Its a great question because people usually think arthritis only happens in adults.

Arthritis is where your joints (eg hips and knees) get sore and swollen (inflammed). There are lots of different reasons that children can get arthritis.

I work on a type of arthritis where your own body tries to attack your joints called Juvenile Idiopathic Arthritis (JIA). “Juvenile” means it affects people younger than 16 years old and “Idiopathic” means we don’t know why it happens. We usually say that children aged 2-4years most commonly get JIA, but your question made me go and look at what the actual youngest age is… The youngest I can find when I search is from Iran where a baby got arthritis in their hip when they were just 20 days old!!

We don’t know why some children get arthritis and some don’t. In JIA we think it is partly due to your DNA/genes and partly due to things that happen during your lifetime and the world around you (your “environment”). It may even be partly due to things that happen to you when you were still in the womb. I think your genes have a lot to do with why you get arthritis, especially for children who get arthritis when they are really young. There is so much we don’t know about why JIA happens in children- this it what makes science so interesting as there are so many questions to try and answer!!