Case Report: Behavioral analysis guided intervention targeting triggers and urges in skin-picking disorder with comorbid onychophagia

Background: Skin-picking disorder (SPD) often co-occurs with onychophagia and can cause substantial functional impairment. Although evidence-based psychotherapies are effective, benefits may be limited when behavioral analysis is not applied explicitly. Case presentation: A 29-year-old man with SPD and onychophagia reported marked occupational impact. Baseline self-monitoring showed 240 min/day of nail-related behavior, 30 episodes/day, and high urge intensity. Using behavioral chain analysis, we mapped perceptual antecedents (visual/tactile irregularities) and diurnal variability of urges. A medication-free, nine-session outpatient program over 20 weeks was delivered, combining stimulus control, urge management routines, and habit reversal training. Outcomes were tracked by daily self-monitoring. Rapid improvement followed initiation of stimulus control and consolidated after urge management routines. By treatment end, daily picking time decreased to 15 min/day (-94%), episode frequency to 5/day (-83%), and urge intensity to 4/10 (-60%); no adverse effects were reported. Conclusion: Making perceptual antecedents and diurnal moderators explicit based on chain analysis enabled a targeted, medication-free intervention that produced clinically meaningful reductions in behavior and urges. A chain-guided behavioral framework may help personalize treatment for SPD and related body-focused repetitive behaviors.