This research will examine the psychometric performance of the electronic diaries for the itch-reported outcome (ItchRO) measure for both patients and caregivers in a stand-alone 2-week validation study in the target patient population. The study is non-interventional in nature; the purpose of the study is to validate the ItchRO prior to the analysis of longitudinal treatment effect data being generated in ongoing clinical trials. Following training and initial completion of the electronic diaries, families will return home and complete the diaries twice daily over the course of two weeks. Additional assessments include the numerical rating scale to assess itching, the patient impression of change (PIC), the caregiver impression of change (CIC), PedsQL (pediatric quality of life), children's sleep habits questionnaire (CSHQ), and clinical scratch scale.