CHARACTERIZATION AND ANALYSIS OF SKIN WEALING BY COMPUTERIZED NONLINEAR-REGRESSION

Weal formation in human skin may be induced by histamine, histamine re leasers and other inflammatory mediators. Weals occur spontaneously in chronic urticaria, and in response to frictional pressure in dermogra phic urticaria. We present an improved method for the analysis of weal ing in human skin by the use of non-linear regression. The method has the advantage of speed, and by the use of non-linear regression permit s the full characterization of the response curves. The time course of histamine-induced wealing is a double exponential function correspond ing to the separate components of weal appearance and disappearance. D ermographic wealing corresponds to an increasing exponential function with increasing pressure. The method of computerized non-linear regres sion is a considerable advance on previous methods for the analysis of urticarial wealing, the effect of vasoactive agents, and their therap eutic action.