Constant sneezing, sudden bouts of cough, itching on the skin, or a rash – all these are symptoms most people experience. The problem arises when these symptoms become persistent, thus causing a lot of difficulties. This is known as an allergic reaction. An allergic reaction can occur due to various reasons. It may be due to pollen in the air, dust particles, an insect bite, or exposure to any substance that the body considers hostile. The immune system pr...