What could cause red splotches on both arms overnight?

Red splotches appearing suddenly on both arms can be concerning and may have various causes ranging from allergic reactions to skin irritation to other medical conditions. It's important to contact a healthcare provider who can properly examine the rash and determine the underlying cause, especially since changes in skin can sometimes be related to treatment side effects or other health considerations in cancer patients.

Thank you....I went to an appointment with my primary care physician and she seems to think I may be allergic to the new medication that they put me on