Don't feel bad if you get lupus and psoriatic arthritis mixed up, because they share some symptoms. If you've got pain and swelling in your joints, it could be a sign of either disease. Your doctor can set you straight, but there are some key ways to tell them apart.
Symptoms of Lupus
Lupus affects everybody differently. The way you feel may not be the same as your friend who also has the disease. Most folks will get flares, which means the condition gets worse at certain times and then gets better. The symptoms can come on slowly or suddenly, and can be permanent or temporary.
Some things you may notice if you have lupus are:
- A rash shaped like a butterfly that covers your nose and cheeks
- You feel tired
- Pain, stiffness, or swelling in your joints
- Sensitivity to sun or light that causes skin lesions
- White or blue color in your fingers and toes when you're in the cold or feel stressed
- Headaches or chest pain
- Ulcers in your mouth or nose
- Hair loss
- Low numbers of blood cells (anemia)
- Swelling in your hands, feet, or legs
Symptoms of Psoriatic Arthritis
Like lupus, your symptoms sometimes get better and sometimes flare up. You may get tired and have pain, swelling, and warmth in your joints.
If you have psoriatic arthritis you may get problems like:
- Severe swelling in your fingers or toes
- Foot pain, often at the bottom or the heel
- Pain in your lower back
- Scaly patches on your skin that flake
- Pitted or discolored nails
What Causes Lupus?
It starts when your immune system -- your body's defense against germs -- attacks your own organs and tissues. The disease causes inflammation and can affect different parts of your body, including your heart, skin, brain, and blood cells.
Experts don't know the exact cause of lupus. They think it may be related to genes that put you at risk for lupus and things you come into contact with that trigger the disease. Some of those triggers are:
What Causes Psoriatic Arthritis?
Psoriatic arthritis can happen if you have psoriasis, a condition that causes your skin to get red patches and silvery scales. Sometimes people get psoriasis first and then have psoriatic arthritis later, but others get the arthritis symptoms first.
Like lupus, psoriatic arthritis happens when your immune system attacks your healthy cells and tissues. This causes your joints to get inflamed and your skin to make too many cells.
It's not clear what causes the immune system to attack your body when you have psoriatic arthritis, but just like lupus, it's likely that genes and triggers play a role.
How Is Lupus Diagnosed?
There's no single test that shows you have lupus. Your doctor will do a physical exam and may ask you to get some blood and urine tests that give clues about your condition. They may also suggest you get a chest X-ray to look for fluid or inflammation in your lungs or an echocardiogram to see if you have problems with your heart.
Your doctor may say you have lupus if you have at least four of 11 signs of the disease that are laid out by experts at the American College of Rheumatology:
- Butterfly-shaped rash
- Raised red patches on your skin
- You're sensitive to light
- Ulcers in your mouth or nose
- Arthritis in two or more joints, plus swelling or tenderness
- Inflammation in the lining of your heart or lungs
- Seizures or other nerve problems
- Too much protein in your urine
- Low blood cell counts
- Certain antibodies in your blood
- Results from a blood test called an ANA test that suggest you may have too many "antinuclear" antibodies, which could be a sign of lupus
How Is Psoriatic Arthritis Diagnosed?
To check if you have psoriatic arthritis, you may need to get certain tests like X-rays to look at changes in your bones or joints, and blood tests that check for inflammation.
Your doctor may also do a physical exam to see if you have inflammation and swelling in your joints or signs of psoriasis on your skin and nails. They will ask you about your medical history.
Your doctor will probably rule out other conditions that can cause similar symptoms. For example, if you only have swelling and pain in a single joint, you may have gout. And if you have no swelling, or very little, you could have osteoarthritis.
Whether you have lupus or psoriatic arthritis, work with your doctor to find the right treatments for you. There are many medicines -- as well as things you can do on your own -- to get relief.