Tumor necrosis factor (TNF) is believed to have a role in the pathogenesis of psoriasis. In this 24-week randomized trial involving patients with moderate-to-severe plaque psoriasis, treatment with etanercept, a TNF antagonist, resulted in significant improvement in the psoriasis area-and-severity index. Rates of adverse events were similar in the etanercept and placebo groups.

Type 1 cytokines are overexpressed in psoriatic plaques. This trial evaluated a monoclonal antibody against interleukin-12 and interleukin-23 in patients with psoriasis. Response rates at 12 weeks were significantly higher in patients treated with interleukin-12/23 monoclonal antibody than in those treated with placebo. Four percent of patients who received interleukin-12/23 monoclonal antibody and 1% of those who received placebo had serious adverse events. Larger studies of longer duration are needed to assess the effectiveness and safety of interleukin-12/23 monoclonal antibody for psoriasis.

Leukocyte-function–associated antigen type 1 (LFA-1) is involved in the pathogenesis of psoriasis. Efalizumab is a humanized monoclonal antibody that binds to LFA-1 and inhibits T-cell activation. This randomized trial demonstrates the efficacy of efalizumab for moderate-to-severe plaque psoriasis. At 12 weeks, 25 percent of patients who received efalizumab had an improvement in a psoriasis index of at least 75 percent, as compared with 5 percent of those who received placebo.

Although methotrexate and cyclosporine are both effective treatments for psoriasis, their comparative efficacy has not been established. This trial compared the two drugs and found them to be similarly effective. Each was associated with specific but limited side effects.

In this 12-week randomized trial comparing two biologic agents known to be effective for psoriasis, ustekinumab (an interleukin-12 and interleukin-23 blocker) was more effective than etanercept (an inhibitor of tumor necrosis factor α). Adverse events associated with the two treatments were similar, but the trial was not large enough and follow-up was not long enough to assess uncommon adverse events.

In this randomized trial of 211 children and adolescents with moderate-to-severe psoriasis, response rates at 12 weeks were higher among patients treated with etanercept than among those receiving placebo (57% vs. 11%, P<0.001). Response was maintained during 24 weeks of open-label treatment. Three serious infections occurred in patients treated with etanercept.

In this 12-week phase 2 trial, a humanized anti–interleukin-17 monoclonal antibody was effective for chronic plaque psoriasis. Larger studies of longer duration are necessary to assess the safety and efficacy of long-term treatment.

In this 12-week, phase 2 trial, an anti–interleukin-17–receptor antibody was effective in treating moderate-to-severe psoriasis. Adverse events included neutropenia. Larger trials of longer duration are needed to assess the risk of infections.

A study of families from southern Tunisia affected by general pustular psoriasis uncovered the genetic cause of their disease: a mutation affecting the function of the interleukin-36–receptor antagonist.

In this 52-week trial, briakinumab was more effective than methotrexate in treating patients with moderate-to-severe psoriasis. Briakinumab may be associated with more serious infections and with cancers.

The skin infiltrates of atopic eczema consist predominantly of type 2 helper T cells, whereas those of psoriasis are mainly types 1 and 17. The two diseases are elicited by different types of antigens and are largely mutually exclusive, since one type of infiltrate antagonizes the other.