Hi
How long has he been having this swelling?
If it had been there for a long time, it might be a dermoid/ sebaceous cyst/
lipoma. Usually none of these swellings are tender to touch unless it has some complications like infection etc.
If you have noticed it only in the past few days and is red and tender, it can be a pyoderma- infection of the skin and hairfollicle. It can present with
fever.
It is likely that his fever and
cough are due to a fresh infection, viral. You may give him
Acetaminophen syrup in a dose of 15mg/kg/dose for his fever, repeated every 6 hours.
Please visit your
Pediatrician, who will tell you what exactly the swelling is, after examination and give you medications for fever and cough too.
Hope my answer helps you.
Wish a speedy recovery for your kid.