Eicosanoid and Cytokine Levels in Acute Skin Irritation in Response to Tape Stripping and Capsaicin
D. M. Reilly, M. R. Green
We assessed the effects of physical and chemical irritants on a profile of acute inflammatory mediators in normal human skin. Skin damage in both cases is accompanied by a flux of inflammatory processes and repair mechanisms, which remain imprecisely understood. We used 10 sequential cellotape strips or topical application of 0.075% capsaicin as skin irritants and characterized the subsequent production and/or release of inflammatory mediators in suction blister fluids from human skin in vivo. In tape stripped skin, levels of prostaglandin E2 and interleukin-1α were increased 3.4-fold and 3.3-fold, respectively (p<0.0001; p<0.02), levels of tumour necrosis factor-α were decreased 3.0-fold (p<0.01), whereas levels of interleukin-6 and leukotriene B4 in blister fluids remained relatively unchanged. For the capsaicin-treated skin, levels of mediators showed only minor differences when compared with matched controls. However, a correlation was observed between levels of prostaglandin E2 and interleukin-1α in capsaicin pre-treated blister fluids (r=0.58, p<0.01, n=19). These data are consistent with prostaglandin E2 and interleukin-1α playing key roles in acute skin responses to mild irritants.