The association of chronic pruritus with patients' quality of life: A cross-sectional study
Authors: Zoe Morgan Lipman, Qai Ven Yap, Jordan Rosen, Leigh Nattkemper, Gil Yosipovitch
Journal: Journal of the American Academy of Dermatology (2021)

To the Editor: The negative association of chronic pruritus (CP) with quality of life (QoL) is well established, with similar burden of disease and effects on self-esteem as chronic pain.1Kini S.P. DeLong L.K. Veledar E. McKenzie-Brown A.M. Schaufele M. Chen S.C. The impact of pruritus on quality of life: the skin equivalent of pain.Arch Dermatol. 2011; 147: 1153-1156Crossref PubMed Scopus (247) Google Scholar Diverse demographic, itch, and diagnostic characteristics have been shown to impact this association.2Carr C.W. Veledar E. Chen S.C. Factors mediating the impact of chronic pruritus on quality of life.JAMA Dermatol. 2014; 150: 613-620Crossref PubMed Scopus (47) Google Scholar,3Kursewicz C. Fowler E. Rosen J. et al.Sex differences in the perception of itch and quality of life in patients with chronic pruritus in the United States.Itch (Phila). 2020; 5: e41Crossref Google Scholar However, the exact nature of these associations remains unclear. In this study, we aimed to examine how demographics and itch characteristics (intensity, duration, frequency, and diagnosis category) impact QoL. A cross-sectional survey was administered to patients with CP at Itch Centers in the Department of Dermatology at the University of Miami and at Temple University from 2015 to 2020. Survey data included demographics, clinical diagnoses, itch intensity (numerical rating scale, 0 to 10), itch characteristics, and the ItchyQoL survey—a self-report survey that measures 21 items and scores QoL into 3 subcategories: symptoms, functioning, and emotions.4Desai N.S. Poindexter G.B. Monthrope Y.M. Bendeck S.E. Swerlick R.A. Chen S.C. A pilot quality- of-life instrument for pruritus.J Am Acad Dermatol. 2008; 59: 234-244Abstract Full Text Full Text PDF PubMed Scopus (154) Google Scholar,5Storck M. Sandmann S. Bruland P. et al.Pruritus intensity scales across Europe: a prospective validation study.J Eur Acad Dermatol Venereol. 2021; 35: 1176-1185https://doi.org/10.1111/jdv.17111Crossref PubMed Scopus (11) Google Scholar The average response rate for all items was 89.4%. Itch diagnoses were divided into 7 categories: inflammatory, idiopathic, neuropathic, systemic, localized, psychogenic, and "other." Statistical analyses were performed using SPSS statistical software, version 26 (IBM), and included general linear model univariate and multivariate regressions for QoL outcomes and Pearson correlation coefficients for continuous variables. The level of significance was P < .05 (unless noted P < .01). Descriptive statistics of study participants can be found in Table I. Within our cohort, the ItchyQoL had a high average overall score of 3.40 ± 0.93. A summary of our comparative statistics can be found in Table II.Table IDescriptive statistics of study participantsCategoryN (%)Mean (SD)Age63057.52 (17.48)Gender Female360 (57.1) Male270 (42.9)Primary racial/ethnic self-identification Caucasian380 (60.3) Hispanic or Latino132 (21.0) African American67 (10.5) Asian17 (2.7) Middle Eastern5 (0.8) Other5 (0.8) Multiple∗Includes Caucasian/Hispanic or Latino (8); Caucasian/African American/Asian (1); African American/Asian (2); Asian/Hispanic (1).13 (2.1) Unknown12 (1.9)Average length of itch history (mo)54278.82 (121.80)Average current itch intensity (NRS)5527.01 (2.61)Frequency of itch (episodes/d) >10215 (34.1) 5-10136 (21.6) 2-4132 (21.0) 158 (9.2) <115 (2.4)Itch diagnosis category Inflammatory274 (43.5) Neuropathic130 (20.6) Chronic pruritus of undetermined origin83 (13.2) Secondary to systemic disease71 (11.3) Localized pruritus of undetermined origin13 (2.1) Psychogenic12 (1.9) Other22 (3.5) Multiple12 (1.9)NRS, Numerical rating scale.∗ Includes Caucasian/Hispanic or Latino (8); Caucasian/African American/Asian (1); African American/Asian (2); Asian/Hispanic (1). Open table in a new tab Table IIComparative statisticsAverage itch intensityOverall QoLSymptom QoLFunctioning QoLEmotional QoLNMean (SD)tMean (SD)tMean (SD)tMean (SD)tMean (SD)tGender Female3607.13 (2.64)1.253.53 (0.91)4.35∗P < .01.3.29 (0.91)3.08∗P < .01.2.53 (1.08)4.23∗P < .01.3.70 (1.06)4.53∗P < .01. Male2706.85 (2.56)3.16 (0.95)3.01 (0.97)3.13 (1.11)3.29 (1.09)Racial/ethnic identification Caucasian3806.91 (2.68)1.313.34 (0.89)1.653.08 (0.92)2.26†P < .05.3.34 (1.07)1.173.46 (1.04)1.09 Hispanic or Latino1327.15 (2.38)1.433.38 (1.03)1.693.27 (0.95)2.54†P < .05.3.23 (1.28)1.023.59 (1.19)1.25 African American677.65 (2.37)1.693.70 (0.88)2.16†P < .05.3.52 (0.95)2.89∗P < .01.3.65 (0.97)1.543.93 (0.97)1.68 Asian176.44 (2.50)1.003.48 (0.85)0.083.10 (0.86)2.17†P < .05.3.62 (1.01)1.433.77 (1.02)1.42 Middle Eastern58.80 (1.64)1.98†P < .05.4.09 (0.41)2.36†P < .05.3.83 (0.70)2.89∗P < .01.4.03 (0.47)1.734.33 (0.63)1.89 Multiple135.77 (3.36)0.643.47 (1.19)1.683.48 (1.04)2.66∗P < .01.3.02 (1.44)0.703.22 (1.50)0.71 Other57.25 (1.05)2.86 (1.13)2.33 (1.18)3.00 (0.81)3.10 (1.37)Frequency of itch (episodes/d) >102157.84 (2.09)6.81∗P < .01.3.72 (0.83)6.03∗P < .01.3.57 (0.93)3.97∗P < .01.3.79 (0.96)4.95∗P < .01.3.89 (0.90)6.33∗P < .01. 5-101367.29 (2.35)5.86∗P < .01.3.41 (0.89)5.04∗P < .01.3.21 (0.92)3.32∗P < .01.3.36 (1.05)3.60∗P < .01.3.59 (1.06)5.41∗P < .01. 2-41326.62 (2.19)4.86∗P < .01.3.13 (0.91)3.21∗P < .01.2.99 (0.92)2.10†P < .05.3.03 (1.03)1.99†P < .05.3.31 (1.09)3.97∗P < .01. 1585.65 (3.50)3.22∗P < .01.2.76 (1.00)1.762.58 (0.82)0.372.80 (1.20)1.232.87 (1.23)2.41†P < .05. <1153.36 (3.20)2.24 (0.73)2.47 (0.66)2.27 (0.95)2.05 (0.92)Itch diagnosis category Inflammatory2746.96 (2.70)1.043.62 (0.89)0.643.44 (0.89)0.553.56 (1.05)0.313.75 (1.03)0.46 Neuropathic1306.98 (2.61)1.043.27 (0.91)-1.253.06 (0.93)-1.893.11 (1.14)-0.683.50 (1.05)-1.08 Generalized CPUO837.30 (2.57)1.403.05 (0.94)-0.532.73 (0.96)-0.793.21 (1.09)-1.013.20 (1.13)-0.27 Systemic717.32 (2.10)1.333.24 (1.01)-0.023.08 (0.91)-0.673.32 (1.14)-0.313.31 (1.14)-0.50 LPUO135.69 (1.75)-0.462.84 (0.76)-1.292.67 (0.84)-1.522.70 (0.95)-1.623.09 (1.09)-1.11 Psychogenic itch127.17 (2.59)0.9443.55 (0.84)-1.052.71 (0.80)-1.523.89 (1.02)0.963.89 (1.09)0.65 Other227.80 (2.09)3.06 (0.95)2.87 (0.86)3.08 (1.25)3.19 (1.12)CPUO, Chronic pruritus of undetermined origin; LPUO, localized pruritus of undetermined origin; QoL, quality of life.∗ P < .01.† P < .05. Open table in a new tab NRS, Numerical rating scale. CPUO, Chronic pruritus of undetermined origin; LPUO, localized pruritus of undetermined origin; QoL, quality of life. Gender significantly impacted QoL, with females displaying higher overall, symptom, and emotional scores while males displayed more impaired functioning. Itch intensity did not differ between males and females. Older age significantly impacted symptom (P = .002, t = 3.076) and emotional (P = .015, t = −2.439) QoL. Age did not correlate with itch intensity. All racial/ethnic groups were associated with a change in symptom QoL, whereas only African Americans and Middle Easterners had decreased overall QoL. Only Middle Eastern ethnicity correlated with increased itch intensity. Greater itch history lengths did not correlate with itch intensity but were found to decrease QoL in all domains (overall P < .001, t = 4.207; symptom P < .001, t = 4.770; functioning P = .001, t = 3.407; emotional P < .001, t = 4.024). Increasing daily itch episodes were associated with greater itch intensities and increased ItchyQoL scores in all domains, specifically those with >2 episodes per day. Itch intensity weakly correlated with all ItchyQoL scores (overall, symptom, functioning, emotional), with Pearson correlation coefficients of 0.412, 0.378, 0.358, and 0.362, respectively. Multivariate regressions revealed significant (P < .01) impacts of gender, itch frequency, and length of itch history for overall, symptom, functioning, and emotional QoL. Our results demonstrate that different etiologies of itch can similarly decrease QoL, although this conclusion is limited by smaller sample sizes of some diagnosis categories. Decreased QoL may have a greater association with female gender, length of itch history, and frequency of itch episodes. While itch intensity was only weakly correlated with decreased QoL, we acknowledge that in a specialized itch clinic, patients may have more severe/debilitating CP than in general dermatology clinics. We hope that this data raises awareness of the various items that may influence patients' QoL. Dr Yosipovitch is Scientific Board Member of Menlo, Trevi, Sienna, Sanofi, Regeneron, Galderma, Pfizer, Novartis, Bayer, Kiniksa, Eli Lilly, Bellus, and AbbVie and reports research support by Pfizer, Sun Pharma, Leo, Menlo, and Kiniksa. Authors Lipman and Yap and Drs Rosen and Nattkemper have no conflicts of interest to declare.