symptoms after 4 days antibiotics

[smartyjones]

last week, my son had a suspicious rash on underarm. rapid was negative, ped put him on antibiotics while awaiting culture. after 4 days on keflex, he has a headache, fever and sore throat. What do you think about developing symptoms after 4 days on abx??

 

he has not been on abx for almost 2 years. this can't be c-diff can it??

 

Thanks for opinions!