PLA2G4D and psoriasis: Although the exact mechanism that triggers psoriasis remains unclear, it is currently accepted that psoriasis is induced or exacerbated by either nonspecific triggers, such as infections [such as Streptococcus (3)], physical injury [such as scratching and tattoos (4)], drugs [such as β blockers, lithium and antimalarials (5, 6)] or some specific autoantigens [such as cathelicidin LL-37, melanocytic ADAMTSL5, lipid antigen PLA2G4D and keratin 17 (7)].