Thank you for your query.
Though you have provided details but I would have appreciated if you had provided the following:
1. When did he contract flu?
2. From when is your son running high fever?
3. From when was the neck pain
and/or swelling present?
4. What are the blood counts?
5. How has been the diabetic control prior to the present fever?
The doctors are doing the right thing as they need to give your son antibiotic and also control his blood sugar.
It is not unusual for infection to settle in the neck. Following flu you son must have developed infection which spreads through blood and can settle down any where in the body. As doctors suspect an accident which must have caused damage around C3 and C4 vertebra, the infection got a chance of settling there. However, without seeing the MRI
and CAT scan reports it is difficult to give any comments.
I hope I have answered your query to your satisfaction.
Wishing your son an early recovery.