Systemic treatments for psoriasis

Systemic medicines target specific parts of the immune system

Systemic treatments for psoriasis work by targeting specific parts of the immune system thought to play a major role in causing the signs and symptoms of psoriasis. When considering a systemic medicine, your dermatologist should consider the severity of your symptoms and help you weigh the benefits of the medicine against the risk of possible side effects.


Biologics are a class of medicine made from living things, like cells. Over the past 10 years, a growing list of biologic treatments have become available to treat moderate to severe plaque psoriasis. They are injected into the skin, or infused with an intravenous (IV) infusion. Biologics work to reduce signals from the immune system that cause your body to make too many skin cells. Different types of biologic medicines can work on different parts of the immune system.

TNF Inhibitors
TNF inhibitors are biologic medicines that work by blocking a protein in your body called tumor necrosis factor (TNF). In psoriasis, there is often too much TNF in the skin, which causes skin cells to grow too quickly. TNF is also a key pro-inflammatory agent.

Interleukin-23/12 inhibitors are a type of biologic that work by blocking the proteins interleukin-12 (IL-12) and interleukin-23 (IL-23). These proteins play a pivotal role in psoriasis.

Interleukin-17 Inhibitor
Interleukin-17 inhibitors are biologics that help block a protein called interleukin-17 (IL-17), which can contribute to inflammation. In psoriasis, there is too much IL-17A in the skin.

Interleukin-23 Inhibitor
IL-23 inhibitors are biologics that block a protein called IL-23, which is thought to be a main stimulator of IL-17.

Skin cells under microscope

Learn about a treatment option for moderate to severe plaque psoriasis


Oral systemics

Cyclosporine is a pill that was approved to treat severe psoriasis in 1997. It is a calcineurin inhibitor that slows skin growth by blocking the activation of certain cells in the immune system. Cyclosporine is generally not used long-term due to side effects, so dermatologists sometimes use it with other systemic medicines.

Oral Retinoids
Acitretin is a man-made form of vitamin A. It was approved for use in the United States in the 1980s. Acitretin is used for severe psoriasis. Retinoids help to slow the growth of skin cells.

Methotrexate has been used to treat severe psoriasis since 1972. It is often prescribed to patients who are not getting results with topical treatments, retinoids, or phototherapy. It is commonly taken as a pill and works on the immune system to slow the quick growth of skin cells and reduce inflammation.

PDE4 Inhibitor
Apremilast is a pill that was approved in 2014 to treat moderate to severe plaque psoriasis in patients for whom phototherapy or systemic therapy is appropriate. It is not known how Apremilast works in patients with plaque psoriasis. What is known is that it inhibits an enzyme called phosphodiesterase 4 (PDE4).

Important information you should know

All medicines have potential side effects and should be used cautiously and under the supervision of a healthcare professional.

Because biologics suppress the immune system, they reduce your ability to fight infection. Biologics can cause serious and sometimes fatal infections. Other serious side effects such as malignancies, severe allergic reactions, blood disorders, and nervous system disorders have been reported. Medication Guides are available for these medications and can help you to better understand the potential benefits and risks of biologic treatments.

Some serious side effects of certain oral systemics include liver damage, birth defects, and decreased kidney function.

Make sure your doctor is aware of any other medications you may be taking.