Pruritis is a common symptom in patients with atopic dermatitis and psoriasis. Patients with atopic dermatitis and psoriasis often report pruritis-associated sleep impairments and scratching behaviors during nighttime and the negative impact on their quality of life. However, nocturnal scratch behavior and sleep impairment are poorly understood due to the difficulties in quantifying these symptoms in patients' daily lives. This study deploys multiple technologies (polysomnography, video capture, wrist sensors, clinician-reported outcomes, and patient-reported outcomes) to develop and validate a wrist-based solution to quantify nocturnal scratch.