My brother had strep and it turned into scarlet fever. does that mean my strep will too?

Not necessiarly: Scarlet fever is just strep that has an associated fever and rash. It does not lead to any other complications and resolves with antibiotic treatment for the strep. Certain strains of strep release a chemical which causes the rash. Whether you get scarlet fever or not depends on which type of strep is causing your infection. See your doctor is you have strep!

Doesn't matter: Scarlet fever is just an archaic name for strep associated with a red rash that often led to intractable high fever (weeks)in the era before penicillin. Today it has no significance other than being a strain marker.About 15-20% of strep strains have an extra gene that codes for a chemical that gives the rash.If you got your strep from bro, you would likely get a rash, but doesn't really matter.