Findings
No uniform definition exists for nocturnal scratching, leading to inconsistencies in data interpretation and measurement across studies.
There are significant differences in how scratching behaviors are defined, recorded, and analyzed, making cross-study comparisons difficult.
The term “nocturnal” is often used imprecisely, as sleep periods vary among individuals (e.g., shift workers, patients with disrupted sleep patterns).
Traditional methods such as videography and clinician observations are expensive, labor-intensive, and impractical for widespread use.
Advances in sensor-based wearables and machine learning present opportunities to create objective, scalable, and patient-centric digital measurement tools.

Recommendations
Define nocturnal scratching as a rhythmic and repetitive skin-contact movement occurring within a delimited sleep period, rather than restricting it to nighttime.
Implement standardized ontologies to guide measurement definitions, ensuring consistency across studies and clinical applications.
Encourage the creation and validation of wearables and machine learning algorithms for objective, scalable measurement of scratching.
Engage researchers, clinicians, patients, and regulatory bodies to drive consensus on measurement definitions and methodologies.
Establish digital measures as key endpoints in clinical trials, supporting their validation and regulatory acceptance.