Psoriasis and Nonalcoholic Fatty Liver Disease.

Nonalcoholic fatty liver disease (NAFLD) is the most prevalent liver condition in the West. The prevalence and severity of NAFLD is higher and the prognosis worse in patients with psoriasis. The pathogenic link between psoriasis and NAFLD is chronic inflammation and peripheral insulin resistance, a common finding in diseases associated with psoriasis. NAFLD should therefore be ruled out during the initial evaluation of patients with psoriasis, in particular if they show signs of metabolic syndrome and require systemic treatment. Concomitant psoriasis and NAFLD and the likelihood of synergy between them place limitations on general recommendations and treatment for these patients given the potential for liver toxicity. As hepatotoxic risk is associated with some of the conventional drugs used in this setting (e.g., acitretin, methotrexate, and ciclosporin), patients prescribed these treatments should be monitored as appropriate. Anti-tumor necrosis factor agents hold the promise of potential benefits based on their effects on the inflammatory process and improving peripheral insulin resistance. However, cases of liver toxicity have also been reported in relation to these biologics. No evidence has emerged to suggest that anti-p40 or anti-interleukin 17 agents provide benefits or have adverse effects.