Pruritus assessment tools for 6 to 7-year-old children: KidsItchyQoL and ItchyQuant

Efficacy of topical and systemic treatments for atopic dermatitis on pruritus: A systematic literature review and meta-analysis

Introduction

Pruritus is a major and burdensome symptom in atopic dermatitis (AD). The number of systemic treatments available for AD has increased recently, enabling improved patient relief.

Objective

To evaluate the effect of AD treatments on pruritus.

Methods

A systematic literature review and a meta-analysis were conducted to evaluate and compare the effects of treatment used in AD on pruritus. PubMed and Embase databases were searched to find articles published between January 1990 and December 2021. Topical and systemic treatments were studied in patients aged ≥10 years.

Results

Among the 448 articles identified, 56 studies were retained in the systematic review. A total of 15 studies evaluated topical treatments: topical corticosteroids (TCS; 2), calcineurin inhibitors (6), PDE4 inhibitors (3), and Jak inhibitors (4). A total of five studies were included in the meta- analysis. All treatments had a positive effect on pruritus, with a mean overall reduction of 3.32/10, 95% IC [2.32-4.33]. The greatest reduction was observed with halometasone (mean: 4.75), followed by tofacitinib 2% (mean: 4.38). A total of 41 studies evaluated systemic therapies: cyclosporine (6), phototherapy (5), azathioprine (2), dupilumab (9), anti-IL 13 (5), nemolizumab (3), Jak inhibitors (9), mepolizumab (1), and apremilast (1). A total of 17 studies were included in 2 meta-analyses according to the concomitant use or not of TCS. In the meta-analysis without TCS, the overall decrease was 3.07/10, 95% IC [2.58-3.56]. The molecules with the highest efficacy on pruritus were upadacitinib 30 mg (mean: 4.90) and nemolizumab (mean: 4.81).

Discussion

The therapeutic arsenal for AD has increased rapidly, and many molecules are under development. The primary endpoint of clinical trials is most often a score that assesses the severity of AD; however, the assessment of pruritus is also essential. The majority of molecules have a positive effect on pruritus, but the improvement varies between them. Efficacy on pruritus is not always correlated with efficacy on AD lesions; therefore, these two criteria are crucial to evaluate. The limitations of this study were the heterogeneity in the assessment of pruritus, the moment of the assessment, and the concomitant application of TCS or not for studies evaluating systemics. In the future, it would be useful to use standardized criteria for assessing pruritus.

Development, Psychometric Validation and Responder Definition of Worst Itch Scale in Children with Severe Atopic Dermatitis

INTRODUCTION

Itch associated with atopic dermatitis (AD) has a profoundly negative effect on patients of all ages. Therefore, itch is a main target for AD therapeutic approaches, and treatments are perceived as beneficial when they achieve an itch reduction. In the absence of a validated scale for children aged 6-11 years that is suitable for assessing itch intensity in clinical trial settings, the Worst Itch Scale was developed.

METHODS

Qualitative interviews, comprising concept elicitation and cognitive debriefing, were conducted to develop and evaluate the content validity of the Worst Itch Scale. Psychometric assessments used data from the LIBERTY AD PEDS phase 3 trial of dupilumab in patients aged 6-11 years with severe AD. These included test-retest reliability, construct validity, known-groups validity and responsiveness. Thresholds for clinically meaningful change were defined using anchor- and distribution-based methods.

RESULTS

The Worst Itch Scale consisted of two items asking about 'worst itching' experienced 'last night' and 'today'. Worst Itch Scale scores showed large, positive correlations with existing patient-reported outcome (PRO) measures of itch, and weaker correlations with clinician-reported outcome (ClinRO) measures assessing objective signs of AD. Improvements in Worst Itch Scale scores were highly correlated with improvements in other itch PROs and moderately correlated with improvements in ClinROs. The responder definition based on the primary anchor, a 1-point improvement in the Patient Global Impression of Disease, was 2.84. Supportive anchors produced response estimates ranging from 2.43 to 4.80 points.

CONCLUSIONS

The Worst Itch Scale is a fit-for-purpose (e.g. well-defined, reliable, responsive and valid) scale for evaluating worst itch intensity in children aged 6-11 years with severe AD. The within-patient threshold for defining a clinically meaningful response was a ≥ 3-4-point change in the Worst Itch Scale score.

TRIAL REGISTRATION

NCT03345914. Video: How can we reliably assess itch intensity in children 6-11 years with severe atopic dermatitis in clinical trial settings?

Prevalence of Itch in German Schoolchildren: A Population-based Study

Itch is a common symptom, but there is limited evidence on the prevalence of itch in children. The aim of this study was to assess the prevalence of itch in schoolchildren. A questionnaire was developed by experts in the field and based on a literature search. The questionnaire was applied in a pilot study of 25 consecutively selected paediatric patients and their parents. It confirmed the high content validity of the questionnaire, and the questionnaire was comparable to hospital records regarding chronic itch (n = 19, mean consistency 89.47%). The questionnaire was distributed among German schoolchildren in 9/12 randomly selected primary schools in Kiel, Germany. Of 1,722 invited students, 443 schoolchildren aged 6–10 years participated, and 26.2% (n = 116) reported itch. The prevalence of acute itch was 20.0% (n = 87), and 14.7% (n = 65) reported chronic itch. Reduced sleep and mood were often related to chronic itch. This study demonstrated that itch is a common symptom in German schoolchildren.

Generation and Validation of the PROMIS Itch Questionnaire - Child to Measure the Impact of Itch on Life Quality

Itch compromises quality of life, but most itch assessments focus only on itch intensity. We aimed to develop and validate a comprehensive PROMIS (Patient Reported Outcomes Measurement Information System®) pediatric measure for itch symptoms and itch impact, defined as the effect specifically of itch on physical, mental, and social health, all of which can affect life quality. After literature review, concept elicitation and cognitive interviews with parents and children with itch, and repeated content-expert review, an item pool was generated and refined. The pool was calibrated with data from 499 pruritic children using exploratory and confirmatory factor analyses, item response theory, and item fit analysis. The resultant 45-item bank, PROMIS Itch Questionnaire - Child (PIQ-C), showed good convergent and discriminant validity in 181 children 8-17 years of age, discriminating children with different levels of severity, and was responsive to change. Strong correlations (rho>.60) were observed with pain and sleep measures, and moderate correlations with other pediatric PROMIS measures. PIQ-C comprehensively measures itch intensity and burden, providing an itch-specific alternative for assessing life quality. The independent calibration of each item/question allows for flexibility in generating short-forms or computerized adaptive testing for efficient use in research and office practice.

What Do We Know about Pruritus in Very Young Infants? A Literature Review

In infants, pruritus is frequently considered as absent because they do not scratch themselves. Because pruritus could induce severe adverse effects in this vulnerable population, we aimed to review existing evidence on the ability of young infants to experience itch and on how to assess itch-related discomfort in this population. A literature review was performed (Pubmed, Google Scholar). Neurological itch pathways are well described. Skin development starts early during gestation. At 34 weeks of gestation, skin is almost complete while skin adaptations occur after birth. Newborn skin is neurologically functional, including the ability for young infants to feel pain. Similarities and interactions between pain and pruritus support the hypothesis that infants could feel pruritus. However, the existence of pruritus in infants has never been evidenced. Many itchy conditions can affect them, suggesting non-negligible prevalence of infant pruritus among which atopic dermatitis (AD) is the most studied disease. Studies reported a negative impact of AD on children and their families. There is no existing validated method to assess pruritus in infants, although they may feel pruritus and chronic pruritus can lead to serious adverse effects. To appropriately diagnose pruritus appears of great interest among young infants. Development of a method is required to this aim.