Help please! could bras with metal underwire cause itching?

Contact dermatitis: I assume your question is if the skin rashes and associated itchiness are caused by metal in your bras. To answer the question, we would first need to take a look at your skin. If it looks like dermatitis only at the contact area with your bras, we would need to check to see if it is due to metal allergy. To do all of that, you need to come see a local allergist.