Psoriasis: A Sequela of Streptococcal Infection Similar to Acute Rheumatic Fever

We propose that psoriasis is a sequela of streptococcal infection similar to acute rheumatic fever (ARF). This hypothesis arises from many different lines of evidence: a markedly elevated serum anti-streptococcal antibody is present in plaque psoriasis. However, cultures are routinely negative in psoriasis because the Group A Streptococcus pyogenes “hides” inside cells and inside biofilms and is thereby unculturable. The activation of either arm of the immune system is likely related to whether internalization or biofilm formation is predominant. With internalization, we postulate it is the adaptive immune system and with biofilm formation, the innate system. Lastly, prolonged treatment with anti-GAS antibiotics is effective in psoriasis as in ARF.