A Study on Scratching Behavior Characteristics in Patients With Various Types of Chronic Pruritus.

Purpose: In the 'Itch-Scratch cycle', scratching manifests in various ways and further provokes skin inflammation and alteration of the skin microbiota. However, there is an unmet demand for classifying and interpreting scratching behavior. We analyze patterns of scratching behavior expressed by patients with chronic pruritus.

Methods: A survey was conducted on 206 adult patients with chronic pruritus for more than six weeks. Participants responded to a questionnaire about pruritus, including standard unidimensional-scale questions, as well as individualistic questions about sensory expression and quality of life. For scratching behavior, all patients answered questions about patterns, tools, situations, time spent, and scratched areas. Exploratory factor analysis was conducted to classify scratching behavior. Descriptive and exploratory factor analyses were used to identify the structure of the underlying factors measured by the questionnaire items.

Results: Among pruritic descriptors, 'unbearable' was the most common (84.5%). Of 206 participants, 190 (92.2%) responded that they scratched. The most common itch resolution methods were 'applying moisturizer', 'rubbing', and 'applying ointment'. The fingernails (89.3%) were the most frequently reported tool used for scratching. Participants reported most frequent scratching during sleep or rest. Among the pruritus-specific quality-of-life indicators, 'Lifelong' was the most stressful item related to all scratching behaviors. Regarding scratching differences by disease, patients with prurigo showed shorter scratching time with abnormal and aggressive behavior.

Conclusions: We analyzed scratching behavior patterns in patients with chronic pruritus. Our findings support the need for education on the importance of applying moisturizer before sleep. The results are also important for helping patients with prurigo correct their abnormal and aggressive scratching behavior patterns, which can reduce quality of life and worsen symptoms.