Improving skin picking diagnosis among Brazilians : validation of the Skin Picking Impact Scale and development of a photographic instrument

Abstract

Background Skin picking disorder is a prevalent disorder frequently comorbid with depression and anxiety, which is underdiagnosed mainly by dermatologists. Assessment of skin picking disorder is based on instruments influenced by the awareness about skin picking disorder and comorbid symptoms. To date, there is no validated instrument for Brazilian individuals nor an instrument to evaluate the severity of skin lesions in an objective way. Objectives Validate the Skin Picking Impact Scale for Brazilian Portuguese and create a photographic measurement to assess skin lesions. Methods The sample was assessed through the Skin Picking Impact Scale translated into Brazilian Portuguese, the Hamilton Anxiety Scale, the Beck Depression Inventory, and the Clinical Global Impression Scale. The patients’ skin lesions were photographed. Photos were evaluated regarding active excoriation, crust/bleeding, exulceration, and linear lesions. Results There were 63 patients included. The Skin Picking Impact Scale translated into Brazilian Portuguese had good internal consistency (Cronbach's alpha = 0.88), which tests of goodness-of-fit, showing a suitable model. The reliability of photographic measurement was 0.66, with a high internal consistency (Cronbach's alpha = 0.87). Photographic measurement was not correlated with the Skin Picking Impact Scale, the Clinical Global Impression Scale, or comorbid symptoms. Study limitations Lack of a previously validated instrument to evaluate dermatillomania in the Brazilian population for comparison. Conclusion The Skin Picking Impact Scale validated in Brazilian Portuguese is a good instrument to evaluate skin picking disorder. Photographic measurement is a consistent way of assessing skin lesions, but it does not reflect the impact of skin picking disorder on the individual's life.