What Does Skyrizi Treat?

Skyrizi is a prescription biologic drug used to treat three specific inflammatory conditions: moderate-to-severe plaque psoriasis, psoriatic arthritis, and moderate-to-severe Crohn’s disease. Its active ingredient is risankizumab, a lab-made antibody that blocks a protein called interleukin-23 (IL-23), which drives inflammation in these diseases. Skyrizi is not a general anti-inflammatory and it is not approved for other conditions.

Understanding what Skyrizi treats means understanding what it does inside the body. IL-23 is a signaling molecule that helps certain immune cells stay active and promote inflammation. In people with these conditions, that pathway is overactive in the skin, joints, or gut. Skyrizi binds to IL-23 and blocks it from triggering those cells. The result, in many patients, is reduced inflammation and fewer symptoms.

What Does Skyrizi Treat?

Skyrizi is approved for three conditions in the United States, and each approval covers a defined group of patients.

• Plaque psoriasis: for adults with moderate-to-severe disease who are candidates for systemic therapy or phototherapy. This is the thick, scaly, red-plaque form of psoriasis, not other types.
• Psoriatic arthritis: for adults with active psoriatic arthritis, a form of arthritis that affects some people who have psoriasis.
• Crohn’s disease: for adults with moderate-to-severe Crohn’s disease, an inflammatory bowel disease.

Each approval has specific wording about which patients qualify. Psoriasis and psoriatic arthritis approvals generally require that the disease be moderate-to-severe. The Crohn’s disease approval is for moderate-to-severe cases, and the drug is typically used after other treatments have not worked well enough.

Skyrizi is not approved for ulcerative colitis, rheumatoid arthritis, eczema, or other inflammatory conditions. That does not mean researchers are not studying it there. It means the current approvals do not cover those uses.

How Does Skyrizi Work in the Body?

Skyrizi is a monoclonal antibody. That means it is a laboratory-made protein designed to attach to one specific target. In this case, the target is interleukin-23.

IL-23 is part of the immune system’s normal communication network. It helps a subset of immune cells called Th17 cells stay active. In healthy people, this system helps defend against certain infections. In people with psoriasis, psoriatic arthritis, or Crohn’s disease, the IL-23 pathway is overactive and keeps inflammation going in the wrong places.

By blocking IL-23, Skyrizi interrupts that cycle. It does not wipe out the immune system. It targets one specific signal. This is why biologics in this class tend to have a more focused effect than older broad immunosuppressants.

One point worth clarifying: blocking IL-23 is not the same as blocking IL-17, another inflammatory signal targeted by a different class of drugs. These are separate pathways, and the drugs that target them are not interchangeable.

How Is Skyrizi Given?

Skyrizi is given by injection or infusion, depending on the condition being treated.

For plaque psoriasis and psoriatic arthritis, Skyrizi is given as an injection under the skin (subcutaneously). It typically starts with two starter doses, followed by maintenance doses given less often. The exact schedule is set by the prescribing clinician.

For Crohn’s disease, treatment usually begins with intravenous (IV) infusions given in a clinic, followed by subcutaneous maintenance injections. The IV loading approach helps get the drug into the body quickly in a disease where fast control of inflammation matters.

Patients are often taught to give themselves the subcutaneous injections at home after training. The IV infusions must be given by a healthcare professional.

How Effective Is Skyrizi?

Clinical trials supporting approval showed meaningful improvement in skin clearing for psoriasis, reduced joint symptoms for psoriatic arthritis, and higher rates of clinical remission for Crohn’s disease compared with placebo. These are the kinds of results regulators reviewed before approving the drug.

What trials cannot tell you is how any one person will respond. Response varies. Some patients see substantial improvement. Some see partial improvement. Some do not respond. A clinician monitors response over time and adjusts the plan accordingly.

It is also important to understand that these drugs manage inflammation; they do not cure the underlying condition. Psoriasis, psoriatic arthritis, and Crohn’s disease are chronic conditions. Treatment aims to control symptoms, reduce flare-ups, and lower the risk of complications.

What Are the Main Risks and Side Effects?

Skyrizi carries a boxed warning about the risk of serious infections. Because it affects immune signaling, it can make it harder for the body to fight certain infections. People with active infections should not start the drug. Anyone on Skyrizi should report signs of infection to their doctor promptly.

Common side effects reported in trials include upper respiratory infections, headache, fatigue, and injection-site reactions. These are not universal, and many people tolerate the drug well.

Other considerations clinicians weigh:

• Skyrizi may interact with live vaccines. Live vaccines are generally avoided during treatment. Patients should discuss vaccination timing with their doctor.
• Because the drug affects immune function, screening for tuberculosis and hepatitis is typically done before starting treatment.
• The long-term safety profile continues to be monitored as more patients use the drug over time.

Anyone considering Skyrizi should review the full prescribing information with their clinician. The risks and benefits depend on the individual’s health history and the severity of their condition.

Who Should Not Take Skyrizi?

Skyrizi is not appropriate for everyone. People with a known serious allergy to risankizumab or any ingredient in the formulation should not take it. People with an active, serious infection should not start treatment until the infection is resolved.

Pregnancy and breastfeeding are areas where the evidence is more limited. Some biologics are used during pregnancy when the benefit is judged to outweigh the risk, but this is a decision that requires a careful conversation with an obstetrician and the prescribing specialist. No clinical guidelines currently provide a simple universal answer for every patient.

Children and adolescents: the safety and effectiveness of Skyrizi in pediatric patients has not been established for all conditions. Some approvals may expand over time as pediatric trials are completed. Parents should ask the child’s specialist about current approval status for their child’s age and condition.

How Does Skyrizi Compare With Other Biologics?

Skyrizi belongs to a class of drugs called IL-23 inhibitors. Other drugs in this class include tildrakizumab and guselkumab. There are also IL-17 inhibitors, TNF inhibitors, and other biologics used for psoriasis, psoriatic arthritis, and Crohn’s disease.

Which drug a clinician chooses depends on the condition, the patient’s history, prior treatments, other health conditions, and patient preference. There is no single “best” biologic for everyone. Head-to-head trials comparing biologics exist for some conditions, but the results do not translate into a universal recommendation.

The evidence does not support the idea that one biologic is superior for all patients. What works well for one person may not work for another. This is why treatment is often a process of trial and adjustment.

The Bottom Line on What Skyrizi Treats

Skyrizi treats moderate-to-severe plaque psoriasis, psoriatic arthritis, and moderate-to-severe Crohn’s disease in adults. It works by blocking IL-23, a specific immune signal involved in inflammation. It is not a cure and it is not approved for other conditions.

For people living with these conditions, Skyrizi is one option among several. The decision to use it should be made with a specialist who understands the individual’s health history, treatment history, and goals. The drug has meaningful evidence behind it for its approved uses, and that evidence should be weighed against its risks.