What Causes Rash All Over The Body While Blood Tests Were Normal?

Thank you. I am having construction done in my home (two bathrooms) when the construction started I got a rash all over my body (gross). I have been to the dermatologist twice (two kenalog shots that haven t done a thing) and been to my regular doctor who took blood to see about a platelet issue. All blood work came back normal (thank goodness). The rash is everywhere except where clothes don t touch (hands, face, feet) …so I am wondering if it could be the drywall…dust etc. It is all over the house and even though we try to clean it up it is still in the air and on our clothes. I m miserable and any info would be so appreicatiated.