Why They Occur and What to Do About Them
Written by Elea Carey
Medically Reviewed on January 15, 2014 by George Krucik, MD, MBA
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Rheumatoid arthritis (RA) is an autoimmune disease that attacks the lining of the joints, causing inflammation. Symptoms of RA include joint pain, fatigue, stiffness, loss of mobility, and low-grade fever.
Some RA medications suppress the immune system. If you have RA and are experiencing a fever, it’s important to find out whether the fever indicates an underlying infection that could lead to complications.
Learn more about RA and fever, and what you can do to feel better.
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A normally functioning immune system can tell the difference between “attackers,” such as germs or viruses, and healthy cells. When the body is attacked by illness, the immune system fights back.
But when autoimmune dysfunction occurs, the immune system mistakes healthy cells for illness, and attacks them instead. In someone with RA, this causes inflammation of the tissue around the joints. RA can also affect the eyes, lungs, and heart.
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Inflammation is a normal part of the immune response in a healthy person. However, in RA, inflammation is part of the problem. It causes considerable pain and reduced mobility.
When inflammation reaches a certain level, the body produces a fever. RA also causes an increase in metabolic rate, which can also result in a fever.
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Rheumatic fever is a serious illness that occurs mostly in children who have recently experienced strep throat. It has similarities to the early symptoms of RA, but is not related to RA.
“Rheum” refers to fluid, and rheumatic fever affects joints. Unlike RA, rheumatic fever only lasts a few weeks. Additionally, rheumatic fever can affect any single joint, and often the same joint on the other side of the body.
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Medicines that suppress the immune system (immunosuppressants) are often used to treat RA. This means that the immune system in an RA patient might not respond effectively to a virus or bacterial infection. Additional illnesses can cause serious complications for RA patients.
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When to Contact a Doctor
Normal body temperature ranges from 97 degrees Fahrenheit to over 99 degrees. Fevers under 101 degrees are not considered serious in adults and are also not uncommon in RA patients.
If your fever rises above 101, contact a doctor so that the underlying cause can be determined. If you have RA, make sure the doctor you see knows this. Be prepared to tell them what medicines you’re using for RA treatment.
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How Do I Know My Fever Is Caused by RA?
The first step in determining if RA is causing a fever is if the patient has been diagnosed with RA. Other signs to look for include:
a fever under 101
no preceding virus, such as flu
no bacterial infection
no other diagnosis (such as cancer)
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RA Fevers in Women
RA usually starts in people over age 40, and affects many more women than it affects men. If a woman over age 40 with RA suddenly feels very hot, it could be RA fever, a fever for another reason, or a menopausal hot flash. A hot flash only lasts a short time. Hot flashes also cause the skin to feel hot, but the internal body temperature often stays normal.
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What Might Help
In case of RA fever, you should:
Drink plenty of fluids.
Keep warm if you’re experiencing chills.
Remove extra layers of clothing and try to keep cool if you’re hot and sweating.
Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen or pain relievers containing acetaminophen, may reduce fever. Be sure to ask your doctor about safe dosage.
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Know What to Do
Low-grade fever is an expected part of having RA. It is usually caused by the inflammation of the joints, or by an improperly working immune system.
Contact a doctor in case of fever over 101 degrees. Fever could indicate an underlying viral or bacterial infection that the immune system has not responded to due to an immunosuppressant.