context: If you have psoriasis, you may have other health problems, too. The itchy skin rash is caused by an issue with your immune system. White blood cells that usually fight infection get activated by mistake, and that triggers inflammation. People who have psoriasis seem likely to have other conditions linked to inflammation like heart disease, diabetes, obesity, non-alcoholic fatty liver disease, and metabolic syndrome. Mild or moderate psoriasis usually is treated with medicines you put on your skin. These probably won't have any effect on most other health issues. But if your psoriasis is severe, you may need drugs that change the way your immune system works. Your doctor should know about any other health problems you have and any medicines you take. If your natural infection-fighting system is weak because of certain diseases (such as HIV) or medications (such as chemotherapy), it can be dangerous to take drugs that affect your immune system. Those include cyclosporine, methotrexate, biologics (drugs made from living cells), and systemic drugs (ones that work throughout your body). Psoriasis, especially if it's severe, seems to make you more likely to have a heart attack or stroke. Treating it can lower your risk, but some medications can hurt more than they help. Both cyclosporine and acitretin ( Soriatane) can raise your cholesterol levels. Cyclosporine can also raise your blood pressure. People with congestive heart failure shouldn't take certain biologics, including etanercept ( Enbrel), adalimumab ( Humira), adalimumab-adbm ( Cyltezo) or adalimumab-atto ( Amjevita), both biosimilars, and certolizumab ( Cimzia), infliximab ( Remicade), infliximab-abda ( Renflexis) or infliximab-dyyb ( Inflectra), biosimilar to Remicade. Psoriasis can make you more likely to get type 2 diabetes, especially if your skin disease is serious. There's some evidence that taking biologic drugs for psoriasis may help your body respond to insulin. And certain drugs that treat diabetes -- thiazolidinedione ( Actos, Avandia) and GLP-1 receptor agonists ( Trulicity, Victoza) -- may also help your psoriasis. But steroids can raise your blood sugar and even lead to type 2 diabetes if you take them for a long time. People with psoriatic arthritis sometimes get steroid injections to ease painful swollen joints, but be careful about that if you have diabetes or are at risk for it. In some cases, topical steroid medicine also may cause blood sugar problems. Follow your doctor's instructions about how much to use and for how long. Some drugs that treat psoriasis can be hard on your liver. Methotrexate can cause scarring, but that usually goes away when you stop taking it. If you have liver disease like cirrhosis or hepatitis or if you drink heavily, you should avoid methotrexate. Acitretin is also not recommended for people with serious liver disease. Severe psoriasis makes you more likely to have chronic kidney disease, and some of the same drugs that treat the skin disease can damage those organs. If you have severe kidney problems, you shouldn't take acitretin, cyclosporine, or methotrexate, and you should take a smaller-than-normal dose of apremilast ( Otezla). Radiation and chemotherapy weaken your immune system. So you shouldn't take systemic psoriasis drugs if you're getting cancer treatment. People with skin cancer also should avoid light therapy, which exposes your skin to ultraviolet rays. Psoriasis may make you more likely to have certain kinds of cancer, like lymphoma and skin cancer. Systemic drugs also appear to raise your risk of these. Crohn's disease and ulcerative colitis may have a connection to psoriasis. One study found that one in 10 women with psoriasis also have a form of inflammatory bowel disease. Two of the biologic drugs used to treat psoriasis can cause these illnesses or make them worse. If you're affected by this, talk with your doctor before you try brodalumab ( Siliq), ixekizumab ( Taltz), or secukinumab ( Cosentyx). When you take a drug that slows down your immune system, like cyclosporine, methotrexate, or biologic drugs, your body can't fight off infection like it normally would. If you have an active serious infection, you shouldn't take these. You should also be tested to see if you've been exposed to tuberculosis or are carrying hepatitis B. Many antibiotics that treat infections shouldn't be taken with systemic drugs. Some change how well your body absorbs the psoriasis drug. Others keep your kidneys from flushing the medicine from your system. That can let it build up to dangerous levels. You may find that your skin clears up when you're expecting a baby. Or it may get worse. Either way, your doctor probably will be very careful in treating your psoriasis while you're pregnant. Try over-the-counter moisturizers or petroleum jelly first. Steroid creams also appear to be safe. But you should avoid tazarotene, a topical retinoid made from vitamin A. Retinoids in pill form are extremely dangerous if you're pregnant. Acitretin can cause serious birth defects. Because it stays in your system a while, you shouldn't try to get pregnant for at least 3 years after you take it. Methotrexate can also cause a miscarriage or birth defects. Men should wait at least 3 months and women 4 months after stopping it before they try to have a baby. Biologic drugs haven't been studied in pregnant women, so talk with your doctor about them. You can pass some medicines to your baby through breast milk. Don't take apremilast, cyclosporine, or methotrexate while you're nursing, and don't use steroid creams on your breasts. Light therapy that uses UVB rays is safe when you're pregnant, but the method called PUVA can cause birth defects. It combines medicine called psoralen with exposure to UVA rays. Women and men shouldn't use this if they're trying to conceive, and women who are pregnant or breastfeeding shouldn't, either. People who have psoriasis are twice as likely to be depressed as people who don't have it. Treating your psoriasis can improve your mood. But some psoriasis medications, like apremilast and brodalumab, may make depression worse.