All these symptoms indicate that your son might be having Pharyngitis
1. Gargle with warm salt water to relieve throat pain.
2. Analgesics like paracetamol
3. Antibiotics (if bacterial infection is suspected)
4. Antihistamine preparations can also be used to provide symptomatic relief.
So...it will be better to consult an ENT specialist
& start treatment as advised.
Meanwhile...make sure that your son avoids cold
food & drinks, maintains adequate hydration & takes soft, non-spicy foods.
Wish him a good health & a speedy recovery.
Let me know if I need to clarify further.
Thanks & take care.