“It’s currently unknown why certain drugs can worsen psoriasis,” says Anna K. Dewan, MD, an assistant professor in the division of dermatology at Vanderbilt University Medical Center in Nashville. “Psoriasis is a disorder of the immune system. It’s thought that these medications alter the immune system in the skin, which subsequently can flare psoriasis.” According to Dr. Dewan, there is also evidence that certain drugs increase skin-cell turnover and lower the ability of skin cells to mature normally.

Common Culprits

Here are some of the drugs that might be in your medicine cabinet which are known to trigger psoriasis flares:

Psychiatric Drugs Lithium, a treatment commonly used to help bipolar disorder and depression, can worsen psoriasis in about half of the people who use it. Other medicines taken to treat anxiety, sleep issues, and panic disorders may also affect your skin. These include Xanax (alprazolam), Klonopin (clonazepam), Prozac (fluoxetine), and Valium (diazepam).Blood Pressure Drugs The beta-blocker Inderal (propranolol) worsens psoriasis in about 25 to 30 percent of people. It’s not known if all beta-blockers will affect your condition.Heart Treatments Some medications used to help heart disease or heart rhythm problems — such as Cordarone (amiodarone) and Lanoxin (digoxin) — can worsen symptoms.Nonsteroidal Anti-Inflammatory Drugs Called NSAIDs, these medicines, including Indocin (indomethacin), are commonly used to treat arthritis, but they can aggravate psoriasis.Oral Steroids Some people can have severe flares after taking a short course of oral prednisone.Anti-Malarials Medicines like Plaquenil (hydroxychloroquine) and Aralen (chloroquine) can trigger a flare. This reaction typically happens two to three weeks after taking the meds.Antibiotics Sumycin (tetracycline), a drug used to treat infections, can exacerbate psoriasis.

Many people with psoriasis can tolerate these medications, but some patients experience negative reactions. “We don’t know why certain people are at risk for having reactions to medications,” Dewan says. “It’s likely an interplay between someone’s genetic risk factors and their immune system.”

Managing Your Meds

Here are some precautions to help lower your chances of a negative drug reaction:

Tell your doctor about your condition. You’ll probably want to tell every physician you see that you have psoriasis. “For a patient with a history of psoriasis, it’s good practice to keep your dermatologist updated as to any newly prescribed oral medications,” says Dewan.Try a different medication. If you notice worsened symptoms, ask your healthcare provider if you can try a different drug that works the same way as your current treatment. For instance, if you’re taking Indocin for pain, you may be able to switch to Tylenol (acetaminophen).Try a lower dose. You might be able to avoid any issues simply by lowering your dose. Be sure to talk to your doctor first.Speak up. Don’t ignore your symptoms. If you experience a reaction, tell your doctor right away. Most of the time, there are alternative treatments that can be used. Your skin doesn’t have to suffer.