Hello, I understand your concern for the raised patches and welts. It appears form your query that you are suffering from the condition of Urticaria or commonly known as hives. It is due to over activity of particular cells called as mast cells. There can multiple causes of the hives including food, environmental, infections and other things coming in contact in day to day life. In my patients I suggest them to use an antihistamine such as loratadine which is non-sedating one or levo-cetrizine at night time. Benadryl is a good option but causes sedation so better to be avoided in day time. Take further guidance form your treating dermatologist. All the best.