I have had a rash on my left arm for over 2 months. It started on the left side of my chest just before the shoulder, then moved to forearm and is now moving up to underarm area. It itches if I touch it, so I have to be conscious not to touch. I went to doctor at beginning of month, and she said contact dermatitis; she gave me a cream, since cortisone cream OTC was not helping. It won t go away. Could it be more? I haven t changed anything I use or eat; I thought it was detergent, so I m no longer using it, and it s only on one arm??