Hello,
Thank you for asking at HCM.
The 2 most common causes of the rashes in children are viral infections and allergic reactions. There are causes also but more rare.
In the case of your granddaughter because she is having the rash for a couple of days, no
fever, she is active and playful this means it is a self limiting cause of the rash, most likely a viral infection that might take a few days and go away on it's own.
If the child starts to scratch, allergic reaction might be the other cause to consider.
Allergy can also cause
vomiting and
diarrhea also and rarely it may cause swollen eyes and lips. If the child gets swollen eyes and lips or is short of breath than she will need urgent referral to the hospital.
It is obvious you are doing the right thing: noticing the right things, playful, no complaints, eating, no new soaps or detergents... I would recommend to continue to watch her the next 3-4 days, and if it is a
viral rash it should disappear by that time. Make sure you do not introduce new food or chemicals that you have not been using for a while.
If she gets any worsening of the rash or she gets any new symptoms you will need to see the doctor as other cause might be considered also.
Hope this answers to your questions and is helpful to you.
Best regards