A sick leave application needs to contain four important pieces fo information:
- What illness you're suffering from
- The date when you expect to be back
- What tasks or information colleagues or coworkers need to be alerted to in your absence
- Contact details in case you need to be reached
Based on the above, here's an example sick leave application you could copy by customizing the fields in bold:
Dear person you are addressing,
Unfortunately I have come down with a case of illness you are suffering from, and so I am writing to submit a formal sick leave application.
After consulting my doctor, I expect to require number of days off to recuperate, and should be back with you by date you will return.
I have left instructions and information that may prove useful in my absence, but please don't hesitate to contact me on your phone number should you need to consult with me about anything.