我全身發紅，騷癢，請問各位高人，是過敏嗎？？

昨天上午突然間感覺後背騷癢，到晚上蔓延至全身騷癢。一個晚上沒睡著，一直在不停的抓啊抓啊，很痛苦。抓過之後全身發紅，越抓越癢。回憶了下，昨天早飯和午飯都沒有吃，不會是食物過敏啊。請高人指點啊

Is there any skin rashes? You may try "Benadryl Spray", which you can get it from local drug store, it does not require prescription

Also try not to scratch it