Out of curiosity, what would've been number 1 on the list? Infection?
1. Infection - Already on antibiotics so no further care necessary.
2. Cyst - Can be fixed with antibiotics and drinking lots of water, etc. Yes, there's a little pain, but nothing more needs to be done.
3. Abscess - Healed with antibiotics but as
@PatrThom said, they'd need to drain it, which can be painful.
4. Cancer - If you have to ask why this is 4th I don't know what to tell you.