What Causes Rash On Abdomen Spreading To Back Area And Legs?

Male. 65. Married.
What is the cause of a rash that began on the stomach and spread to the back and now the legs, arms and hands. Rash itches. Feels raw if rubbed. Began 3 days ago. Doctor 2 days ago asked if we'd changed laundry detergents, which we have not, and the rash has spread since that appointment. No fever but body aches and joint pain. Wife has flu which came on about same time -- head cold, body aches, no fever. Recently spent 3 weeks traveling -- Colorado, skiing.
Thank you for your help.