After reading your history it appears that you urticaria
or hives. This is common problem and we see so many of cases in normal population. So do not worry about it. There are so many of the aggravating factor and in yourself including day to day factors of environment. You can take benadryl
or levocetrizine or fexofenadine
by mouth daily. You can apply calamine lotion over the affected area. Stay away from hot and humid climate and wear cotton clothes.