(click the picture for a larger image)
This photoquiz is only for non members of the CC to answer because most of them already know of my boy's recent malady. He is one year old and was unusually cranky and needy for about 2 days, then was noted to have felt hot at different times by his mother and I on the same day, but his temperature was not measured. He continued to be uncharacteristically pissy for another two days, but without anymore signs of fever, before finally developing this rash, which was when all the pieces of the puzzle fell into place. If you have an infant or toddler, know this one. It could help you avoid giving your child antibiotics unnecessarily, and subsequently branding your child as "allergic" to amoxicillin (or whatever antiobiotic your doctor gives when he/she doesn't have a good diagnosis and you don't want to leave the office emptyhanded).
UPDATE: The answer is in the comments, it is kind of long and preachy. alternative points of view are welcome.