If you were sitting at a club frequented by upper-crust gentlemen, your companions might frown on you for scratching yourself. Perhaps, a discrete rubbing of your afflicted area may be more appropriate. If your skin were to itch, whatever manner you chose to deal with it, deal you must. Your skin is a thin layer that keeps everything inside together. Usually, your skin works in harmony with your body to protect you from the outside world. Sun, dust, allergens, pollution and what not, your skin is your first line of defense. Just below the surface lies a layer of nerves, hair follicles but also immune cells called dendritic cells.
An allergy occurs when the immune cells in your skin react to what would otherwise consider harmless. The trigger can come from the food you eat, cosmetics you use, a fancy perfume you sprayed or even a plant that you accidentally touched while strolling in the garden. It may take a while for your body to react to the trigger. This delay is because the allergens contain molecules called haptens that bind to your immune cells. If your immune cell decides that the invading allergen, say your fancy perfume, is dangerous, it will mark it to be eliminated.
Once a particular type of allergen has been marked as dangerous, it is permanent. Your body is now set up to eliminate it each time you are exposed. The next time you will not be so fortunate and the time between exposure and reaction will be instant. You will break out into a rash; your body will itch and gentleman’s club be damned you will have little option but to scratch the itch. Your body is now trained to eliminate the invader permanently. The best way to avoid an allergic reaction is to prevent your body from getting trained to recognize it to be dangerous. The only way to do this is to catch it early before your body makes up its mind.