What causes psoriatic arthritis?

Psoriatic arthritis (PsA) is an inflammatory, autoimmune condition that can affect both the joints and skin. The specific cause of psoriatic arthritis is not fully known, though it’s believed that an overproduction of molecules in your body may activate any of the multiple symptoms of PsA. 

When these molecules, such as the IL-17A protein, are overproduced, your body’s immune system has inflammatory responses that can contribute to pain and swelling in the joints and tendons, and sometimes, even skin plaques—raised patches of red skin that are thick, scaly, and itchy. 

Without proper treatment, PsA may worsen, which is also known as psoriatic arthritis flares. And if left untreated, psoriatic arthritis may cause permanent joint damage. 

Psoriatic arthritis (PsA) isn’t caused from overuse of joints or aging. It’s the result of an overactive immune system.

What are the first signs of psoriatic arthritis?

The first signs of psoriatic arthritis are not the same for everyone and can affect each person differently. PsA symptoms can include:

Skin Image
Skin Image

Skin plaques and nail changes

Joint Damage Image
Joint Damage

Joint pain, reduced range of motion and physical ability

Range of Motion Image
Range of Motion Image

Pain and swelling commonly felt in hands, feet, and joints

Tenderness in Joints Image
Tenderness in Joints Image

Tenderness in and around joints, tendons, and ligaments

Sausage Fingers Image
Sausage Fingers Image

Sausage-like fingers or toes

Back Pain
Back Pain Image

Fatigue, back pain, and stiffness

Swollen Joint
Swollen Joint Image

Joint damage: if left untreated, psoriatic arthritis may cause permanent joint damage

Men and women are equally at risk of developing Psoriatic Arthritis (PsA)

Men and women are equally at risk of developing PsA

What are the symptoms of psoriatic arthritis?

There are multiple symptoms of psoriatic arthritis, like joint pain and fatigue. These symptoms affect everyone differently. Click or tap on the person below to learn more about these symptoms and how they can affect you.

Quotes from actual patients who were compensated for their time.


Ask your rheumatologist if COSENTYX® may be right for you. 

Real people taking COSENTYX are looking and feeling better. Could you be one of them?

Actual Patient Jorge

“My symptoms started very early in my life, probably when I was around 25 years old.” 

—Jorge, Actual Patient

Individual results may vary. Jorge was compensated for his time.

"There was a lot of pain in my joints—especially in my hips, then in my knees and lower back. I really struggled to walk.”

—Tina, Actual Patient

Individual results may vary. Tina was compensated for her time.

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COSENTYX® (secukinumab) is a prescription medicine used to treat:

  • people 6 years of age and older with moderate to severe plaque psoriasis that involves large areas or many areas of the body, and who may benefit from taking injections or pills (systemic therapy) or phototherapy (treatment using ultraviolet or UV light alone or with systemic therapy)

  • people 4 years of age and older with active enthesitis-related arthritis

  • people 2 years of age and older with active psoriatic arthritis

  • adults with active ankylosing spondylitis

  • adults with active non-radiographic axial spondyloarthritis and objective signs of inflammation

Important Safety Information

Do not use COSENTYX if you have had a severe allergic reaction to secukinumab or any of the other ingredients in COSENTYX. See the Medication Guide for a complete list of ingredients.

COSENTYX is a medicine that affects your immune system. COSENTYX may increase your risk of having serious side effects such as:


COSENTYX may lower the ability of your immune system to fight infections and may increase your risk of infections, sometimes serious.

  • Your doctor should check you for tuberculosis (TB) before starting treatment with COSENTYX.
  • If your doctor feels that you are at risk for TB, you may be treated with medicine for TB before you begin treatment with COSENTYX and during treatment with COSENTYX.
  • Your doctor should watch you closely for signs and symptoms of TB during treatment with COSENTYX. Do not take COSENTYX if you have an active TB infection.

Before starting COSENTYX, tell your doctor if you:

  • are being treated for an infection
  • have an infection that does not go away or that keeps coming back
  • have TB or have been in close contact with someone with TB
  • think you have an infection or have symptoms of an infection such as: fevers, sweats, or chills; muscle aches; cough; shortness of breath; blood in your phlegm; weight loss; warm, red, or painful skin or sores on your body; diarrhea or stomach pain; burning when you urinate or urinate more often than normal

After starting COSENTYX, call your doctor right away if you have any signs of infection listed above. Do not use COSENTYX if you have any signs of infection unless you are instructed to by your doctor.

Inflammatory bowel disease

New cases of inflammatory bowel disease or “flare-ups” can happen with COSENTYX, and can sometimes be serious. If you have inflammatory bowel disease (ulcerative colitis or Crohn’s disease), tell your doctor if you have worsening disease symptoms during treatment with COSENTYX or develop new symptoms of stomach pain or diarrhea.

Serious allergic reactions

Serious allergic reactions can occur. Get emergency medical help right away if you get any of the following symptoms: feeling faint; swelling of your face, eyelids, lips, mouth, tongue, or throat; trouble breathing or throat tightness; chest tightness; skin rash or hives (red, itchy bumps). If you have a severe allergic reaction, do not give another injection of COSENTYX.  

Before starting COSENTYX, tell your doctor if you:

  • have any of the conditions or symptoms listed above for infections.

  • have inflammatory bowel disease (Crohn's disease or ulcerative colitis).

  • are allergic to latex. The needle cap on the COSENTYX Sensoready® 150 mg/mL pen and the 150 mg/mL and 75 mg/0.5 mL prefilled syringes contains latex.

  • have recently received or are scheduled to receive an immunization (vaccine). People who take COSENTYX should not receive live vaccines. Children should be brought up to date with all vaccines before starting COSENTYX.

  • have any other medical conditions.

  • are pregnant or plan to become pregnant. It is not known if COSENTYX can harm your unborn baby. You and your doctor should decide if you will use COSENTYX.

  • are breastfeeding or plan to breastfeed. It is not known if COSENTYX passes into your breast milk.

Tell your doctor about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements. Know the medicines you take. Keep a list of your medicines to show your doctor and pharmacist when you get a new medicine.

How should I use COSENTYX?

See the detailed Instructions for Use that comes with your COSENTYX for information on how to prepare and inject a dose of COSENTYX, and how to properly throw away (dispose of) used COSENTYX Sensoready pens and prefilled syringes.

  • Use COSENTYX exactly as prescribed by your doctor.

  • If your doctor decides that you or a caregiver may give your injections of COSENTYX at home, you should receive training on the right way to prepare and inject COSENTYX. Do not try to inject COSENTYX yourself, until you or your caregiver has been shown how to inject COSENTYX by your doctor or nurse.

The most common side effects of COSENTYX include: cold symptoms, diarrhea, and upper respiratory infections. These are not all of the possible side effects of COSENTYX. Call your doctor for medical advice about side effects.

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch, or call 1-800-FDA-1088.

 Please see full Prescribing Information, including Medication Guide.