Stelara (ustekinumab) is a medication that has been approved by the U.S. Food and Drug Administration (FDA) for the treatment of several medical conditions, including psoriasis, psoriatic arthritis, and Crohn’s disease.

Plaque psoriasis starts within your body. Your immune system regulates cell growth throughout the body including skin cell growth. Plaque psoriasis, a chronic skin condition, is caused by an overactive immune system. 

This means that some cells are rapidly being produced and these excess cells can lead to overgrowth of skin cells. With nowhere for those overgrown skin cells to go, they pile up on the skin and lead to the plaques you see on the surface of the skin.  

Similarly, the cause of Crohn’s disease and ulcerative colitis are not fully understood but it is suspected to also be caused by an overactive immune system response. It is thought that genetics, environmental factors, and an imbalance inflammatory response leads to the inflammation found in Crohn’s and UC. 

The prolonged inflammation in these two conditions lead to the symptoms that each person experiences. If left untreated, it can lead to damage in the GI tract. There are proteins in the body that contribute to inflammation and once they are activated, can lead to a chain reaction that leads to an inflammatory response.

Stelara is a biologic medication that is given initially by infusion then maintained by routine injections. It works by targeting certain proteins in the body that play a role in inflammation. By blocking these proteins, Stelara helps to reduce inflammation and improve symptoms associated with psoriasis, psoriatic arthritis, and Crohn’s disease.

Stelara targets two specific proteins in the body called interleukin-12 (IL-12) and interleukin-23 (IL-23). These proteins are involved in the immune system’s response to infections and other threats to the body. 

In people with psoriasis, psoriatic arthritis, and Crohn’s disease, IL-12 and IL-23 can trigger an excessive immune response that leads to inflammation and tissue damage. By blocking these proteins, Stelara helps to reduce inflammation and improve symptoms.

By blocking IL-12 and IL-23, Stelara may reduce inflammation that is prevalent in rheumatic conditions and irritable bowel diseases.