S100A8 and rosacea: Continuous gastric inflammation induced by cytotoxin-associated gene A (CagA) or vacuolating cytotoxin A-positive H. pylori strains has been shown to increase the levels of vasoactive substances such as histamine and prostaglandins through the activation and degranulation of mast cells.31,38 Similar to D. folliculorum, there is also an increase in pro-inflammatory cytokines including IL-8.39 This may contribute to the chronic inflammation and vasodilation observed in rosacea.