Final answer:
If Evan compulsively washes his hands more than 50 times a day due to a fixation on germs, he likely has Obsessive Compulsive Disorder, a condition featuring unwanted obsessions and compulsions.
Step-by-step explanation:
If Evan washes his hands more than 50 times a day due to an ongoing fixation with germs, he is most likely suffering from Obsessive Compulsive Disorder (OCD). This disorder is characterized by persistent and unwanted thoughts (obsessions), and repetitive, ritualized behaviors (compulsions) that the person feels driven to perform in order to alleviate anxiety. While hand-washing is a crucial part of personal hygiene and public health, particularly before eating and after using the toilet, excessive hand-washing like that seen in OCD can actually be detrimental to the skin and does not necessarily provide additional health benefits. In contrast to a simple hygiene practice, OCD-related hand-washing is usually not grounded in a rational desire to prevent illness, but rather in an inability to control repetitive actions linked to obsessive thoughts about contamination.