Was he hit in the face? Its unlikely that he woud have the mumps, however anything is possible. I think a trip to the doctor would be your best bet. Good luck

Aye it could be syphilis, or the like

Firstly see a doctor.

He may not have mumps it could be something else with similar symptoms.

However saying that there are fears that there was a batch of innefective vaccine. If he does get the mumps dont worry its not that uncommon and at least he can never get it again.

Remember soft, non acid foods - althought apparently lemon and honey perhaps in tea may help to relieve nausia