[Quantified determination of dermographism in patients with atopic eczema]

The usual method of checking dermatographism (D), which is typically white in atopic eczema (AE), allows only a qualitative rating. To allow reproducible quantification of D we have developed an easily used instrument, called a Dermographometer. This can be fitted with one to three blunt tapered metal bars of different weights applying a constant stretching pressure over the whole skin areas to be examined or different pressures at isolated points. We used this device to study D in 27 patients with AE and in 20 healthy controls. Of the 27 patients, 21 had white D, 2, red D, and 4, none at each pressure applied. In 18 of the controls D was red. In addition, the two groups differed significantly in the time to onset and the duration of the D elicited, which was much longer in patients with AE. Simultaneous and constant application of distinct grades of pressure for quantitative dermatographometry is a method that can reliably be used for the study of inter- and intraindividual variation in vascular reactivity in the course of various dermatoses, especially.