Thank you for your consult at DoctorSpring.com.
Your description of your child's symptomatology is spot-on and accurate. It fits well into the natural history of strep. The rash is also suggestive. Get your child's throat examined by a pediatrician as soon as possible. Clinical evidence of strep infection include palatal petechiae, congested pharynx and tender cervical lymph nodes.
Clues to scarlet fever could be presence of a beefy red tongue, sand paper rash and pastia lines on the skin. So go ahead and take him to the pediatric emergency.
Hope that this helps you decide.
MBBS, MD (Pediatrics), PGDCRL