[Biologics. New drugs, new adverse reactions].

Biologics have been available in Germany for the treatment of moderate to severe chronic plaque psoriasis and/or psoriatic arthritis since 2004. They include chimeric (human/mouse) or fully human monoclonal antibodies or recombinant fusion proteins. The currently available biologics are cytokine antagonists, which neutralize either TNF-alpha or the interleukins IL-12 and IL-23. Unexpected adverse events result either from their potential immunogenicity or from their mode of action, which consists in neutralizing the biologic activity of the respective cytokines. In particular the increased risk for severe infections that may take an atypical course during biologic therapy deserves attention in daily clinical practice.