Skin allergies (allergic contact dermatitis) can cause body wide hives, wheezing or other systemic symptoms. Non-allergic contact dermatitis usually results in a small itchy rash and is a reaction to different substances in soaps, detergents, nickel, fragrances, sunscreens, plants and latex (to name a few). Additionally heat, immune system disorders, medications and infections can cause skin allergies.
Allergic contact dermatitis occurs when your skin comes in direct contact with an allergen. For instance, if you have a nickel allergy and your skin comes in contact with jewelry made with even a very small amount of nickel, you may develop red, bumpy, scaly, itchy or swollen skin at the point of contact.
Atopic dermatitis (eczema) is a chronic skin condition related to immune dysfunction in the layers of the skin. It usually begins in infancy or early childhood. It is often associated with asthma, allergic rhinitis (hay fever) or food allergy.
Coming in contact with poison ivy, poison oak and poison sumac can also cause allergic dermatitis. The red, itchy rash is caused by an oily coating covering these plants. The allergic reaction can come from touching these plants, or by touching clothing, pets or even gardening tools that have come in contact with the oil.
Additionally, some individuals with eczema have a food sensitivity which can worsen eczema symptoms.
Urticaria (hives) are an inflammation of the skin triggered when the immune system releases histamine, causing small blood vessels to leak leading to swelling in the skin. Swelling in deep layers of the skin is called angioedema.
Although often uncomfortable and sometimes painful, hives and eczema are not contagious.
Angioedema is swelling in the deep layers of the skin, often seen with urticaria (hives). Angioedema most often occurs in soft tissues such as the eyelids, mouth or genitals.
Angioedema is called "acute" if the condition lasts only a short time (minutes to days). This is commonly caused by an allergic reaction to medications or foods. Chronic recurrent angioedema is when the condition returns over a long period of time.