Biologic drugs . Biologics contain human or animal proteins and can block certain immune cells that are involved in psoriasis. They’re usually recommended for people with moderate to severe psoriasis and are administered via an injection or IV infusion. There are currently three types of biologics that can help treat psoriasis, all of which block immune system chemical messengers that promote inflammation called cytokines. The three types of biologics block the cytokines tumor necrosis factor alpha (TNF-alpha), interleukin 12, interleukin 23, and interleukin 17-A (IL-12, IL-23, and IL-17A, respectively).
While it's not exactly a type of psoriasis, psoriatic arthritis affects up to 30% of people with psoriasis and usually develops five to 10 years after the original psoriasis diagnosis (although it can show up before a skin diagnosis). The primary symptoms are pain and stiffness in a joint or joints. Morning stiffness, which can take 45 minutes to loosen up, and tendinitis are two other signs. If a person with psoriasis develops joint symptoms that last more than a few weeks, they should be evaluated to see if they have developed psoriatic arthritis. People with mild psoriasis might be just as likely to develop arthritis as someone with a severe form of the disease. Although psoriatic arthritis is not as debilitating as other forms of arthritis, it should be controlled to minimize pain and maximize joint function.
Methotrexate (MTX) is the antimetabolite most often prescribed by dermatologists for moderate-to-severe psoriasis. Hepatotoxicity is the primary clinical concern when planning long-term methotrexate therapy. Mild transaminase elevations (less than twice the upper limit of normal) are to be expected during therapy, but these levels do not correlate with hepatic fibrosis. A 2009 consensus conference advocates following the American College of Rheumatology guidelines for patients with no risk factors for liver injury and recommend considering liver biopsy or switching to another treatment after to 4 g to total cumulative methotrexate dosage. Folic acid (FA) supplementation at 1 mg daily is recommended to abate the gastrointestinal side effects of methotrexate without reducing efficacy (although many providers hold FA on the day of MTX therapy). It also helps to prevent megaloblastic anemia.