Timing of scratch and limb movements during sleep in children with atopic dermatitis.

In this retrospective analysis of children with atopic dermatitis (n = 6) who coincidentally had a video polysomnography, we found that most nocturnal limb movements in children with atopic dermatitis are non-scratch versus scratch, 109.0 ± 67.9 vs. 15.3 ± 5.4 (p = 0.01). Average scratch duration was 8.4 ± 2.7 s, which was not different by sleep stage. Scratch movements are distinct in timing, occurring most often during N2 sleep, in the first third of sleep, and peaking at 90 minutes after sleep onset, corresponding with completion of the first sleep cycle.