One option is create an account on Wikipedia and add the Paris Hilton entry to your watchlist. But it's so inefficient because you'll have to keep revisiting the webpage every now and then.
Thankfully, your job gets much easier because Wikipedia now provides XML Feeds (RSS & Atom) for recent changes to any Wiki article. So the moment anyone changes your boss' entry, your newsreader would notify you almost instantly.
How to subscribe to Wikipedia RSS feeds ?
Click the history tab and then choose RSS or Atom feed in the toolbox section on the left sidebar. You will get feeds in the following format.
You can construct your own Wikipedia feeds by replacing Paris_Hilton with any other term like Adobe_Photoshop or Google. No need to visit the Wikipedia even.
Tip: Wikipedia doesn't support instant email notifications for article changes yet but you can use ChangeNote or WatchThatPage services.
Related: How to Change Wikipedia Default Layout & Color Scheme