Emerging Contaminants: An Important But Ignored Risk Factor for Psoriasis

Industrialization and modernization have changed the environment. A group of emerging contaminants (ECs) has been defined recently. Psoriasis, whose incidence has increased in recent years, is a relapsing immune-mediated disease carrying a heavy disease burden. The erythematous scaly plaque is a typical symptom and occurs on several parts of the body. In addition, psoriasis has many comorbidities, such as psoriatic arthritis, diabetes, and depression, damaging the quality of life of patients. IL-17, IL-12, IL-23, and TNF-alpha are important related cytokines. ECs can influence psoriasis through the immune system and inflammatory responses. Specific mechanisms include increasing pro-inflammatory cytokines such as TNF-α and IL-17, and activating immune cells such as macrophages. And for psoriasis patients, it is suggested to reduce the exposure of most ECs. However, the complex mechanisms involved have not been discussed together and concluded. In this review, we summarize the relationship between ECs and psoriasis, focusing on the immune system, especially the immune cells and cytokines. These results can help guide clinical treatment and long-term management of psoriasis.