Sleep disturbance in patients with lichen simplex chronicus and its relationship to nocturnal scratching: A case control study.

BACKGROUND

Lichen simplex chronicus (LSC) is a common pruritic disorder resulting from repeated rubbing and scratching. Nighttime pruritus is a common feature in LSC and may disrupt the sleep pattern. The aim of this study is to determine whether there are sleep abnormalities in patients with LSC.

PATIENTS AND

METHODS

Fifteen patients with LSC and 15 age-, sex- and body mass index-matched control subjects were enrolled in the study. No participant had any other medical or psychiatric illness. All subjects were evaluated by overnight polysomnography, scratch electrodes, Epworth sleepiness scale and a general questionnaire for demographic data and sleep problems.

RESULTS

There were no significant differences in the groups for total sleep time, sleep efficiency, sleep latency, rapid eye movement (REM) latency, percentage of stage 1 non-REM sleep and REM sleep. The percentage of stage 2 non-REM sleep was higher (P < 0.05) and the percentage of slow wave sleep (stages 3 and 4) was lower in the study group (P < 0.05) than in the controls. The patient group had a mean of 15.9 +/- 7.5 arousal index and 22.8 +/- 14.1 awakenings compared with 9.5 +/- 3.1 and 10.4 +/- 3.9, respectively, in the controls (P < 0.05, P < 0.01, respectively). Arousals of patients were mainly observed in non-REM sleep. The number of scratching bouts ranged from 6 to 20 per night. Scratching episodes were observed frequently during stage 2 non-REM sleep.

CONCLUSION

Polysomnographic findings of patients with LSC demonstrated that sleep structure is disturbed by arousals and awakenings related to scratching bouts during sleep.