How do physicians diagnose scarlet fever?
In most cases, the patient's history and physical exam will result in a presumptive diagnosis of scarlet fever. However, throat swabs (or rarely wound or other sites of infection) are cultured to determine if GABHS are present. Unfortunately, there are many other infections that can cause both a skin rash and a fever. Isolation of GABHS usually is enough to confirm the diagnosis of scarlet fever. If GABHS is not identified, the symptoms are likely due to another underlying problem.