The itching around the anus at night is caused by the following conditions: 1. It is possible that pinworms crawl out of the anus in the middle of the night to lay eggs while the anal sphincter is relaxed, so there is itching around the anus at night. 2. It is possible that the acromegaly is caused by infection with the human papilloma virus, and there are uneven, hard masses near the anus. The actual fact is that you can find a lot of people who are not able to get a good deal on this kind of things.