Something touches your skin, and your immune system thinks it's under attack. It overreacts and sends out antibodies to help fight off the invader, called an allergen. The result is a red, itchy rash where the substance was on your skin.
Your doctor calls this allergic contact dermatitis. People who have allergies react to things that wouldn't bother most others. The rash looks like irritant contact dermatitis, but it can happen with only a brief touch of a small amount.
Having a food allergy used to mean dining out was limited to carrying your plate from the kitchen to the porch or, at best, eating at the home of a close friend or relative who could guarantee your food offenders were nowhere in sight.
Today, however, eating out is a lot easier -- and safer -- for the 2 million Americans who suffer with a mild, moderate, or even a severe food allergy. One reason: Restaurants are more aware and more prepared.
"The awareness of food allergies has definitely increased...
Anything from plants like poison ivy to dyes and fragrances found in everyday products might be allergens.
You could also have an allergic reaction to something in the air that settles on your skin, like plant pollen, chemical sprays and powders, fibers, or cigarette smoke. Airborne contact dermatitis mostly happens on your eyelids, head, and neck. It can be very hard for doctors to diagnose.
Skin allergies can also cause hives and swelling deep in the skin.
If you can't avoid contact with your trigger, you can usually treat the rash and ease the itching. And you can't pass it to anyone else.
What Causes Skin Allergies?
It takes at least 10 days to become sensitive to something after your first contact with it. You might even be able to touch something for years before you have an allergic reaction to it.
But once you've developed an allergy, you could have a reaction within a few minutes of coming into contact with it. Or it may take a day or two.
Latex, which is used in stretchy things like plastic gloves, elastic in clothing, condoms, and balloons
Some chemicals will cause a reaction only when they're on your skin and in the sun.
You're more likely to have certain skin allergies if you a have skin condition such as eczema (also called atopic dermatitis), inflammation in your lower legs because of poor circulation, and itching in your private parts, or you often get swimmer's ear.