Psoriasis is a chronic skin disease where red, scaly, itchy patches break out all over your body. It’s an autoimmune disease in which your immune system goes haywire and triggers inflammation of your skin.
Psoriasis can also raise your risk of many types of cancer, including lymphoma. Lymphoma is cancer in your lymph nodes, spleen, bone marrow, or thymus gland. These glands and organs help your body fight off infections.
Your risk of lymphoma is still low overall, but you’re three times more likely to develop this cancer than if you didn’t have psoriasis. If you’re 65 or older and have psoriasis, you have an even higher risk for lymphoma.
Why Psoriasis Raises Lymphoma Risk
It’s unclear why psoriasis could raise your risk of lymphoma or other types of cancer. Here are a few theories:
- Chronic inflammation in your body may increase cancer risk.
- People with psoriasis tend to have other health problems that also raise your risk of cancer, such as smoking, heavy alcohol drinking, obesity, or metabolic syndrome. Metabolic syndrome is a group of health problems like high blood pressure, high cholesterol, high blood sugar, and excess belly fat.
- Some psoriasis medications have been linked to lymphoma risk. People with severe psoriasis may be more likely to take these drugs to control their skin disease. Recent research shows that biologics used to treat severe psoriasis do not increase your risk of lymphoma.
Psoriasis Severity and Lymphoma
Both people with mild and severe psoriasis are at higher risk for all types of lymphoma.
People with psoriasis are at the most risk for one type called cutaneous T-cell lymphoma (CTCL). If your psoriasis is severe, you’re at higher risk for CTCL than those with milder psoriasis.
One possible reason is that psoriasis can cause your lymph node cells to grow out of control, which then evolves into cancer. These white blood cells are also called T cells, and they increase and spread in both psoriasis and CTCL, and there may be common genes that drive this cell growth in both psoriasis and CTCL.
Mild and severe psoriasis both carry the same risk of another type of lymphoma called Hodgkin’s lymphoma, but only people with mild, not severe, psoriasis are at slightly higher risk of non-Hodgkin’s lymphoma, another form of this cancer.
What About Different Types of Psoriasis?
Does the type of psoriasis you have affect your lymphoma risk? In 2021, a new analysis of 25 different studies found that people with moderate to severe plaque psoriasis have a higher risk of all types of blood and lymph node cancers, including Hodgkin’s and non-Hodgkin’s lymphoma, multiple myeloma, and leukemia, and a much higher risk of CTCL.
Psoriatic arthritis, an autoimmune disease that causes both psoriasis skin patches and swollen, painful arthritis in your joints, doesn’t seem to increase risk of lymphoma or other cancers.
Pustular psoriasis is a rare type that causes pustules, or raised skin bumps. Pustular psoriasis may occur along with plaque psoriasis or appear on its own. It’s possible that pustular psoriasis may increase your risk of lymphoma.
In some rare cases, CTCL causes skin bumps on the palms or soles of the feet that are mistaken for pustular psoriasis. Doctors could miss this cancer unless they do a biopsy, or tissue sample test.
Could My Psoriasis Meds Cause Lymphoma?
People with severe psoriasis may take methotrexate, a drug that lowers the immune system and has also been used to treat cancer. It’s rare, but some people who take methotrexate can develop lymphoma or other bone marrow diseases years later.
People with psoriatic arthritis often take strong, immune-suppressing drugs like biologics, but they tend to have low rates of lymphoma. These medications calm the overactive immune system and inflammation in psoriatic arthritis. By doing so, they may also slow down the process that causes lymphoma. While immunosuppressants were once thought to increase your risk of cancer, recent research suggests that this may not be true.
While some research suggests that people who take TNF inhibitors do have higher rates of lymphoma, a large study from 2019 found that TNF inhibitors don’t raise the risk of new or recurring cancer in people with psoriasis or other autoimmune diseases.
Are There Other Risk Factors?
People of color, children, and teens are at higher risk for mycosis fungoides, the most common form of cutaneous T-cell lymphoma. It’s a slow-growing cancer that causes patchy, scaly, red skin rashes.
CTCL skin patches may appear lighter or darker than the rest of your skin if you are a person of color. Early on, your CTCL skin patches may be mistaken for psoriasis.
Pustular psoriasis is more common in people of Asian ethnicity than whites or other groups, and is more common in women than men.
Is There Anything You Can Do?
These steps may help you lower your lymphoma risk if you have psoriasis:
- Quit smoking. Smoking increases your risk of lymphoma. Your risk of lymphoma will drop after you quit and keep going down in time.
- Stay at a healthy weight. Being overweight or obese may raise your risk of lymphoma. Eat a healthy, balanced diet of fresh foods. Cut back on processed foods, red meats, and sugar.
You may not be able to prevent lymphoma, but you may catch it early. See your doctor if you notice symptoms like enlarged lymph nodes: painless, hard bumps in your armpit, neck, or groin. Other early signs of lymphoma are fever, chills, night sweats, weight loss, swollen belly, and fatigue.
