Hi,thanks for query.It seems that this could be due to some viral infection.At times this kind of rash
are common in viral infection.The also subside readily with viral also.Give her plenty of fluids to drink,keep a possibility of allergy
in mind and watch for possible allergen like soap,some food etc.You can apply lacto calamine
over it,if they do not resolve please see your primary care
physician for this.
wishing you good health.