What's the point of sitting at home and working anyway, you ask? Well, for one thing your seniors won't mind that you're not coming in -- offering to work from home shows commitment towards your responsibilities.
Also, stating that you're not well is sure to grant you some concession -- nobody will expect you to do as much work as when you're at the office.
But if you are assigned something to do, make sure you deliver. Don't volunteer only to back out with half-hearted excuses like 'I'm suddenly feeling worse' or 'My Internet connection is down.'
Also read: 10 things to avoid at your job interview