Scarlet fever us a form of the streotococcal disease characterized by a skin rash. The streptoocci secrete a toxin which causes a skin rash to appear. Ordinarly scarlet fever evolves from the initial illness of strep throat, although the rash only occurs in 10% of the cases of step throat. Scarlet fever can also be present in those who are suffering from other infections caused by the streptococcal bacteria, such as a streptococcal infection of the skin an soft tissue, surgical wounds, or the uterus.