Trichotillomania & Excoriation: Trichotillomania is characterized by recurrent pulling out of one’s hair, resulting in hair loss, as well as repeated attempts to decrease or stop hair pulling. Excoriation is characterized by recurrent skin-picking, resulting in skin lesions, as well as repeated attempts to decrease or stop skin picking. These symptoms must cause a high level of distress or impairment in functioning (social, occupational, or other important areas).