Does the effectiveness of biological medications in the treatment for psoriasis depend on the moment of starting therapy? A preliminary study.

Introduction: It is well known that biological medications acting on selected elements of the immune response are highly effective in psoriasis treatment. It is a common perception that psoriasis is a seasonal disorder with improvement in warmer months, however it has not been unequivocally confirmed. It is not known whether the time of year of starting systematic therapy for psoriasis influences treatment outcomes. Material and methods: Changes in psoriasis severity scores during treatment with biologics were investigated. The scores were recorded for 62 patients with moderate to severe psoriasis at the beginning, after 1, 4 and 7 months of the therapy. Patients were divided into two groups: those beginning the treatment in the cold period of the year (November-March) and in the warm period (May-September). The seasonal groups were also divided into subgroups according to the type of biologics used: interleukin inhibitors and tumor necrosis factor α (TNF-α) inhibitors. Results of the treatment were analysed using standard statistical tests of differences between samples. Results: After 1 and 4 months of the therapy, better efficacy of interleukin inhibitors was found in patients starting treatment in summer. The course of psoriasis improvement in patients taking TNF-α inhibitors resulted in consistent improvement regardless of the season. The outcome of the treatment after 7 months was similar for both seasonal groups and types of biologics used. Conclusions: Our understanding of the effectiveness of the treatments depending on the time of the year combined with the type of biologics used, may further improve results of the therapy.