The Strep body rash is usually associated with strep throat infection caused by streptococcus bacteria. The patient suffer from high fever and tonsillitis. The strep body rash appear after 48 hours of the sore throat. After completion of the treatment of throat, this rash start to fade after one week and complete recovery take place after 1-2 weeks. In sever cases it can take many weeks. So I advise you not to take any medicine for this rash and wait for 2-3 weeks.