Allergies

A skin allergy is when skin becomes irritated because the immune system reacted to something that is usually harmless. This is called an allergic reaction. An allergic reaction can cause rash, itching, burning, redness, bumps, hives, and swelling. Many different allergens can cause a reaction. Below are some of the most common allergic skin conditions:

Atopic dermatitis (dur-muh-tahy-tis), or eczema, is when the skin becomes easily irritated, itchy, and dry. It is the most common allergic skin condition, and is more common in children than adults. Eczema is linked to both genetic (inherited from parents) and environmental factors. It is connected to asthma, food allergies, and seasonal allergies. Some things can make eczema flare up, such as certain foods, stress, soaps and lotions, or cold and dry air.

Allergic contact dermatitis is when something touches the skin and causes a reaction. For example, some people are allergic to the metal nickel and will have a skin reaction if jewelry made with nickel touches their skin. A reaction to poison ivy is another example. Many people have an allergic reaction to the oil on a poison ivy or poison oak plant.

Urticaria (ur-ti-kair-ee-uh), or hives, are raised bumps on the skin that form because of an allergic reaction. These bumps are also called welts or wheals. A person may get hives after eating a food they’re allergic to. The bumps are a result of histamine that the body releases in response to the allergen. Things besides allergies can cause hives as well, such as a bug bite.

Angioedema (an-jee-oh-i-dee-muh) is swelling deep in the skin. It often happens on places like the eyelids, lips, and throat, and often happens together with hives.

Symptoms

The symptoms of a skin allergy vary depending on the type of reaction:

->  Eczema causes an itchy, scaly, red, dry rash, especially on the face, hands, elbows, and knees. Sometimes eczema weeps clear fluid as well.

->  Allergic contact dermatitis causes a rash that may be itchy but is often painful. The rash may have both raised bumps and blisters. The reaction may happen right away or it may be up to 48 hours after your skin was exposed to whatever is causing it to react.

->  Hives are raised, flat, itchy bumps that may also be tender. Hives are a sign of a potentially serious allergic reaction.

->  Angioedema is a type of swelling. For example, angioedema on the eyelid can cause your eye to be swollen shut. When it happens in the throat, it is an emergency because the swelling makes it hard to breathe.