Computer analysis of nocturnal scratch in atopic dermatitis

Abstract

Scratch behavior was monitored with a paper strain gauge attached to the dorsum of the hand and an amplifier. The all-night recording was subsequently analysed every 60 sec with a specially devised computer system and the duration of scratching and the time(s) of its occurrence were printed out. This technique was applied in 10 patients with moderate or severe atopic dermatitis, 5 with generalized eczema and 5 non-itchy subjects. It was found that scratching occurred in cluster(s) or in an isolated form in both itchy and non-itchy subjects. Marked clustering of scratch behaviour was noted only in itchy subjects. No specific difference was observed in scratch patterns of atopic dermatitis vis-?-vis generalized eczema. Total scratch time of the right and left hands during the night ranged between approx. 1 and 5 thousand sec in itchy patients and between 1 and 5 hundred sec in non-itchy subjects. The ratio of the total scratch time to the recording time in atopic dermatitis did not differ significantly from that in generalized eczema. No correlation was observed between the duration of scratch and serum lgE level.