It usually takes a few days for bacterial or normal
viral tonsillitis to clear, but it can take weeks if mononucleosis is the
cause. Because of possible complications associated with bacterial tonsillitis, doctors usually give antibiotics.
One complication of bacterial infection, rheumatic fever, used to be common until doctors started treating bacterial tonsillitis with antibiotics. Group A streptococcus can spread through the body and infects vital organs, especially the heart.