SHORT COMMUNICATION
513
Nocturnal Pruritus: Prevalence, Characteristics, and Impact on ItchyQoL in a Chronic Itch Population
Michael J. LAVERY 1 , Carolyn STULL 1 , Leigh A. NATTKEMPER 1 , Kristen M. SANDERS 1 , Helen LEE 1 , Shwetapadma SAHU 2 ,
Rodrigo VALDES-RODRIGUEZ 1 , Yiong-Huak CHAN 3 and Gil YOSIPOVITCH 4
Department of Dermatology, Lewis Katz School of Medicine, Temple University, Philadelphia, 2 College of Medicine, University of Tennessee
Health Science Center, Memphis, USA, 3 Biostatistics Unit, Yong Loo Lin School of Medicine, National University of Singapore, Singapore,
Singapore, and 4 Department of Dermatology and Itch Center, Leonard M. Miller School of Medicine, University of Miami Health System, 1600
NW 10 th Avenue, Rosenstiel Medical Science Building – Room 2023, Miami, FL 33136, USA. E-mail: [email protected]
1
Accepted Nov 2, 2016; Epub ahead of print Nov 2, 2016
Chronic pruritus is a distressing condition with a lifetime
prevalence of 25.5% (1). Itch is often reported to be
especially bothersome during the evening and at night.
Nocturnal pruritus (NP) is a reported feature of both
dermatologic and systemic conditions and can interfere
with the initiation and maintenance of sleep, resulting in
deleterious effects on health, functionality, and emotional
wellbeing (2, 3). In adults with atopic dermatitis (AD),
sleep deficits attributable to NP have been shown to pro-
foundly affect quality of life (QoL), functional ability,
and cognition (4). In patients with psoriasis, NP has been
implicated as a cause of decreased work productivity
(5). Furthermore, in hemodialysis patients, pruritus and
related sleep disturbances have been associated with a
17% increased mortality risk (6). However, specific,
in-depth studies of NP are lacking. We used validated
questionnaires to determine the prevalence, characteris-
tics, severity, and impact on QoL of NP in the chronic
itch patient population (7, 8).
MATERIAL AND METHODS
This study was conducted from April 2015 to March 2016 in
the outpatient clinic at Temple Itch Center. All English-speaking
individuals between the ages of 10 and 100 with a diagnosis of
chronic pruritus were eligible to participate. Chronic pruritus was
defined as itch present for ≥ 6 weeks (9). Subjects with dementia
were excluded from participation. This study was approved by
the Temple University Institutional Review Board, and signed
informed consent was obtained from each participant.
A total of 160 subjects with a mean ± SD age of 57 ± 16 were
included in the study. Ninety-seven (60.6%) participants were
female, and 63 (39.4%) were male. Subjects were identified as
Caucasian (65.6%), African American (23.1%), Hispanic/Latino
(5.6%), Asian (1.9%), and other (3.8%).
All participants were asked to complete two validated ques-
tionnaires: the itch questionnaire (7) and the itch quality of life
survey (ItchyQoL) (8). The itch questionnaire assessed the se-
verity of itch and several associated characteristics, including the
presence and severity of NP and the degree of sleep disturbance.
Overall ich severity was quantified using an 11-point numeric
rating scale (NRS) anchored at 0, representing “no itching,” and
10, representing “worst itch imaginable.” Itch characteristics,
including itch severity at different times of day, were measured
on a scale anchored at 0 (not at all), 1 (to a minimal extent), 2 (to
a mild extent), 3 (to a moderate extent), an