My 9 year old son had strep 4 weeks ago and just got it again . doc gave a stronger antibiotic clindamycin. when will the white pus on tonsil go away?

A week or so: Strep is usually not resistant to antibiotics. Some times the antibiotics have a hard time penetrating into the tissue. Sometimes kids can have a year with multiple strep infections. Don't worry. It gets better.

Virus or strep?: The white stuff you see is called an exudate. Tonsillitis with exudate is not always caused by strep. That's why it is important to take a throat culture to make a definitive diagnosis you child may have an adenovirus which cause exudative tonsillitis but does not respond to antibiotics.