Visual symptom provocation in skin picking disorder: an fMRI study

Skin-picking disorder (SPD) is a common mental disorder characterized by recurrent and excessive picking of dermatological irregularities. Different disorder models have been developed to explain this behavior, but empirical evidence is still scarce. One model (the disgust-related disease avoidance model) suggests that SPD might be understood as pathological grooming elicited by skin imperfections that singal possible infection. Twenty-five women with SPD and 19 matched controls viewed and rated images depicting skin irregularities and smooth skin during functional magnetic resonance imaging. The participants did not engage in picking behavior. Relative to controls, SPD patients reported more disgust and urge to pick when looking at skin irregularities. This was accompanied by greater activation in the insula and amygdala, and stronger insula-putamen coupling. Disgust feelings elicited by viewing skin irregularities were positively correlated with activation of the insula and the putamen, in the clinical group. On personality questionnaires, the SPD patients reported elevated self-loathing and problems in regulating their disgust feelings. The current study provides first evidence for altered disgust processing in SPD patients.