Skyrizi (risankizumab-rzaa) is a prescription drug used to treat certain autoimmune conditions, including plaque psoriasis and Crohn’s disease. It works by attaching to specific proteins in your immune system and reducing inflammation.

Note: The reason “-rzaa” appears at the end of the drug’s name is to show that the drug is distinct from similar medications that may be created in the future.

Doctors prescribe Skyrizi to treat certain autoimmune diseases in adults. This drug is a selective immunosuppressant, which means it works by suppressing certain immune system functions. The following sections explain how the drug works to treat the conditions doctors prescribe it for.

For plaque psoriasis

Skyrizi is prescribed to treat moderate to severe plaque psoriasis in adults who can use light therapy or systemic therapy (therapy that affects the whole body) for their condition.

Plaque psoriasis causes thick patches of skin that are discolored on your elbows, knees, lower back, or scalp. These patches, called plaques, can itch or bleed.

Skyrizi works by attaching to certain proteins in your immune system. This helps ease the inflammation that leads to plaques on your skin. Reducing inflammation can lead to clearer skin.

For psoriatic arthritis

Skyrizi is used to treat active psoriatic arthritis. “Active” means you’re experiencing symptoms of psoriatic arthritis.

Symptoms of psoriatic arthritis include:

  • joint pain
  • swollen fingers or toes
  • scaly patches of skin
  • nail pitting
  • fatigue (low energy)
  • eye redness or pain

Skyrizi works by attaching to certain immune system proteins. This helps decrease the inflammation that causes psoriatic arthritis symptoms. By reducing this inflammation, Skyrizi can ease such symptoms.

For Crohn’s disease

Doctors may prescribe Skyrizi to treat moderate to severely active Crohn’s disease. This condition occurs from digestive tract inflammation, often in your colon or small intestine.

Symptoms of Crohn’s disease include:

  • abdominal cramps
  • diarrhea
  • fatigue
  • bloody stool
  • sensation of an urgent need to have a bowel movement

Skyrizi works to treat Crohn’s disease by attaching to certain proteins in your immune system. This helps lower the inflammation that causes Crohn’s disease symptoms. Reducing this inflammation helps relieve symptoms of this condition.

For ulcerative colitis

Skyrizi is used to treat moderate to severely active ulcerative colitis. This condition causes inflammation and sores that typically affect your colon. Symptoms of ulcerative colitis may include:

Skyrizi works to treat ulcerative colitis by attaching to certain proteins in your immune system. This helps reduce the excess inflammation that contributes to ulcerative colitis symptoms. The inflammation reduction can help restore your colon’s lining and improve its function while easing symptoms.

Skyrizi starts working after your first dose. In the drug’s studies, some people experienced a reduction in symptoms in the following time frames:

  • For plaque psoriasis: after 16 weeks of treatment
  • For psoriatic arthritis: after 16 weeks of treatment
  • For Crohn’s disease: within 8 weeks of starting treatment
  • For ulcerative colitis: after 12 weeks of treatment

It’s important to note that your results with Skyrizi may differ from those in studies. Talk with your doctor to learn more about what you can expect from your Skyrizi treatment.

Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.