The cause of psoriasis is unknown, but Streptococcal infection may trigger guttate psoriasis or flare-ups of chronic plaque psoriasis. Tonsillectomy may prevent or reduce the severity of throat infections, and limit the Streptococcus reservoir.

Why does strep cause psoriasis?

It is currently not understood why, following streptococcal infection, only some people experience psoriatic outbreaks. One possible explanation is that the tonsil micro-environment of these individuals promotes the generation of inflammatory T cells that drive the skin disease.

What bacteria causes psoriasis?

It seems clear that the skin microbiota may have a role in the pathogenesis of chronic plaque psoriasis. Corynebacterium, Propionibacterium, Staphylococcus, and Streptococcus have been identified as the major bacterial genera.