Hi, I can understand your concern for itching in upper arm. There can be multiple possibilities of your concern and it is too early to make a diagnosis. It can be simple dryness or pruritus seen due to anxiety also. The only precaution you must follow is not to touch, pinch pop or squeeze any of them other wise it can get infected and can cause complications. You can apply medium potency steroid cream application such as mometasone or fluticasone cream. You can take antihistamine benadryl or loratadine by mouth. Take care.