Sterile trauma to normal human dermis invariably induces IL1beta, IL6 and IL8 in an innate response to "danger".

Microdialysis allows the study of the local production and temporal resolution of cytokines in living skin. Samples were taken from the normal skin of 10 healthy subjects for 24-28 h after insertion of a concentric microdialysis catheter, and analysed with a Luminex bead-based assay. Interleukin-1 beta (IL1b), IL6 and IL8 were seen in all subjects at all time-points after the first hour. Levels peaked at 5-8 h, equilibrating to lower levels at 24 h. Immunohistological double staining for human leukocyte antigen (HLA)-DR and intracellular cytokines on biopsies taken after catheter removal showed many stained cells in the dermis, in contrast to the few cells stained in the epidermis. This study demonstrates the reactive capability of the dermis when provoked separately from the epidermis. The production of IL1b, IL6 and IL8 occurs invariably in what can be termed an innate, dermal response to "danger"; in this case in the form of sterile needle trauma.