The inability to control the urge to pick is similar to the urge to compulsively pull one's own hair, i.e., trichotillomania. Researchers have noted the following similarities between trichotillomania and excoriation disorder: the symptoms are ritualistic but there are no preceding obsessions; there are similar triggers for the compulsive actions; both conditions appear to play a role in modifying the arousal level of the subject; and the age of onset for both conditions is similar. There is also a high level of comorbidity between those that have trichotillomania and those that have excoriation disorder. A notable difference between these conditions is that skin picking seems to be dominated by females whereas trichotillomania is more evenly distributed across genders.