Thank you for writing to JustAnswer with your health question. I am sorry that no one had yet answered your questions. I am just logging on and saw your post has been waiting since this morning earlier.
Do you have a fever, or any other symptoms? Depending on this information is how we would determine if this is an emergency. But whether it is emergency or not, you should see the doctor for this. An urgent care clinic, or calling your doctor might be more appropriate than going to the ER. The ER is usually just for stabilizing a person, and they do not usually go into depth on determining a cause of a problem, unless it is life threatening.
Some people are born with sensory processing problems, but it is unusual for this type of problem to just "appear out of no where".
Sometimes with fibromyalgia there is very sensitive skin, as well a muscular pain.
I hope this helps. If you have questions or comments, please reply so that I can help you with them.