If you've ever been out hiking in the woods, you probably know to avoid certain plants: poison oak, poison ivy, and poison sumac, for example. They're all off-limits, unless, of course, you want to suffer from a painfully itchy rash.
Cooks, hair stylists, doctors, nurses, orderlies, or those working in any type of cleaning service know how rough the chemical and conditions at work can be on their skin.
Why is it that certain plants and substances cause these agonizing skin reactions for certain people? The red, inflamed reaction is technically called contact dermatitis. In essence, it's the skins reaction to coming into contact with something it finds annoying.
If you experience skin inflammation when you touch something like a plant or metal, it is contact dermatitis.
There are two types of contact dermatitis: irritant and allergic.
Irritant Contact Dermatitis
The majority of contact dermatitis cases are the irritant type. This type happens when substances (soaps, solvents, fiberglass, etc.) directly injure the skin. While this type normally affects the hands and forearms, it can occur in any part of the body that comes into contact with the irritating substance.
Jobs that require frequent exposure to heat and water—such as food preparation, dishwashing, and hair styling—can make skin more prone to irritant contact dermatitis.
Allergic Contact Dermatitis
Allergic contact dermatitis occurs when your body's immune system reacts to an allergy-causing substance. Dermatitis can also be atopic, meaning it comes from a hereditary tendency towards excessive Immunoglobulin E (IgE) reaction. Atopic dermatitis is also called "eczema."
Learn more about atopic dermatitis (eczema).
Skin allergies affect up to one-quarter of Americans at some point in their lives. Those allergies have a variety of causes, and produce similar—but often subtly different—rashes and other symptoms.
What Are Allergies?
An allergic reaction happens when your immune system has an overblown response to a substance that isn't normally harmful.
Typically, our immune systems respond to dangerous external elements by producing groups of cells known as Immunoglobulin E (IgE) antibodies. These antibodies normally protect us from harmful irritants and toxins, like bacteria and viruses, which can cause infections and other illnesses.
Basically, antibodies in the immune system are the body's security guards. For those with an allergy, however, that security works too hard.
When an allergic reaction occurs, the immune system is overly sensitive to certain substances, thinking they are harmful even though they are actually harmless. This sensitization triggers an inflammatory response sparked by the release of IgE and eosinophils (white blood cells produced in the blood marrow) and other cell types. They start attacking because they perceive a threat to the body, when in all actuality there is no threat at all.
What is an Allergic Reaction?
A true allergic reaction cannot occur without an initial exposure to an allergen, sensitization (when IgE is previously induced by that exposure), and then another exposure.
Most of the time, reactions are mild, with site-dependent symptoms such as a skin rash, hives, itchiness, or swelling. Occasionally, however, an allergic reaction can produce a more challenging and dangerous outcome—anaphylactic shock, for example, which is an emergency situation during which breathing can become difficult and blood pressure can drop precipitously. Anaphylactic shock is almost never caused by skin allergies.
Treating allergic reactions has become somewhat more effective with powerful drugs introduced over the past several years. The best strategy by far, though, is prevention—staying away from known allergens in order to keep irritation and even more significant symptoms from developing in the first place. Without doubt, preventing symptoms by eliminating exposure to allergens is the gold standard for allergy control.
