Scarlet fever is characterized by prodrome of
abdominal pain and
fever followed by appearance of rash 1-2 days after onset of illness, first on the neck and then extending to the trunk and extremities. The exanthem is usually coarse and the erythema blanches with pressure. A few days following generalization of the rash, it becomes more intense along skin folds and produces lines of confluent petechiae known as the Pastia sign. These lines are caused by increased capillary fragility. The rash begins to fade 3-4 days after onset, and the desquamation phase begins. This phase begins with flakes peeling from the face. Peeling from the palms and around the fingers occurs about a week later and can last up to a month. Diagnosis of scarlet fever can be established by throat culture for streptococcus and ASLO test.