Hi Doctor, My Son Is 19 And Has Had This Condition Sir Throat, Fever And These Ulcer/blisters In His Mouth Are Symptoms Of Foot And Mouth Disease Called, Herpangina?

Question: Hi Doctor,
My son is 19 and has had this condition for 6 days now. It started with a sore throat. Then a sudden fever, the fever went away and then he developed these ulcer/blisters in his mouth...the throat, roof of his mouth and way deep in his throat...he went to the doctor, they did a strep test and that was negative, said it was a virus. 2 days later it was so painful he couldn't eat and barely drink. He then went to a local walk in clinic and the doctor there thought it was strep, that the test the other doctor gave him was a false negative, and he also tested him for mono...mono was negative...so he gave him an rx for antibiotic thinking it was strep...well he still has these terrible ulcers and they just don't stop coming and he still is unable to eat and barely drink...I'm so worried about him...I wanted to take him back to the doctor and he wanted to give it another day. He thinks he has a form of hand, foot and mouth disease called, herpangina. We thought maybe he does as he was at a friend's farm recently....we are at a loss and so worried...what do you think? The sores that are way down in his throat are so sore he can barely talk.

He also developed some of these ulcers/blisters on his tongue yesterday as well

That is terrible...so how would he have gotten this? Is this something he is going to continue to get for the rest of his life? Is this like genital herpes? Is this like cold sores?

Thank you

Thank you for your help...it is very disheartening, but will move forward the best we can.