Chinese crested hairless dog full body rash?

My female chinese crested has a full body rash and has had it for a few days. She has red bumps on her skin right now. She is itchy but isn't showing any other signs of distress other than that. The only thing that I can think of is that since she wears clothes (shes hairless and gets cold) that she might be allergic to the detergent we use to wash her clothes. The only thing that is stumping us it that she also has a polar fleece outfit that she just got, that has NOT been washed yet so has not been exposed to our detergent. Does anyone have any experience with this?