Some RA drugs, such as biologics, affect the immune system, your body’s defense against germs. You may not be able to fight off illnesses as easily as you used to. That’s why you need to be on the lookout for a fever. It could signal something serious, either very active disease or an infection. Infections can get worse quickly if you’re taking medication that keeps your immune system from working, so it’s important to get treatment quickly.
Fever can be a sign of infection. RA medications like biologics and steroids slow down your immune system. While they ease joint pain and swelling, it’s harder for you to fight off bugs like the flu. RA makes you more likely to get an infection just because the disease wears down your immune system. Mild fever is also one sign of an RA flare. That’s when inflammation gets out of control. If it gets too high, your doctor will check for infection.