 [ Symptoms ] will valtrex help with the rash that i broke out with after my son was diagnosed with mononucleosis if not what will  i had mononucleosis when i was 14 i am 46 now my son was diagnosed with mononucleosis and then i broke out in a rash on my hands and fore arms will valtrex help the rash and if not what will it is very itchy and looks terrible [ Disease ] valtrex will not help a rash related to mononucleosis there are thousands of medical conditions that can result in a rash so it would not be wise to associate your son is mono with your rash the rash seen in mono does not usually itch since i cannot see your rash and examine you over the internet i would advise you to see a medical provider so you can be properly diagnosed