Dermatitis (Eczema)

Home » Dermatitis (Eczema) » Contact Dermatitis

Questions to Ask Your Doctor about Allergies
(Free Handout)

Contact Dermatitis

Contact dermatitis is an eczema-like skin reaction that is produced by exposure to an irritating substance such as detergents, soaps, certain plants, and solvents. It can also be caused by an acquired hypersensitivity to an allergen, which is a substance that causes an allergic reaction. The first exposure to a particular allergen does not trigger a reaction or irritation, but causes the person to develop sensitivity. Subsequent exposure then produces an itchy rash.

Causes

Irritant contact dermatitis is caused by substances that are harsh to the skin. Substances that commonly cause the condition include detergents and soaps, bleaches, solvents, acids and alkalis, bubble baths, and even urine and feces. Infants have thin, sensitive skin that is easily irritated and reddened, and people with disorders that alter the skin's protective barrier are more susceptible to irritation by harsh substances. Other skin rashes and moist, chafed areas make one particularly susceptible as well.

Allergic contact dermatitis develops after sensitivity and further exposure to an allergenic substance. Examples of this include reactions to contact with poison oak or poison ivy; nickel plating on earrings, watches, and belt buckles; and rubber or glues in shoes. Some allergens, such as sunscreens and fragrances, become sensitizing only when exposed to the sun.

Signs and Symptoms

Acute eruptions of allergic contact dermatitis are characterized by redness, swelling, and blistering of the exposed areas. As the eruption evolves, crusts and scales may form. In chronic conditions, the skin darkens, thickens, and often cracks. The eruption may not be characteristic, however, and the diagnosis may not be immediately obvious.

The shapes and locations of allergic contact dermatitis provide the most helpful diagnostic clues. Lesions can present in linear or square patches or develop at telling sites such as underneath a watch, on the earlobes, or under a waistband.

Allergic contact dermatitis of the face can result in swollen, red, and blistered skin. The responsible allergen is sometimes difficult to determine because there's been exposure to multiple reaction-inducing agents. For example, someone may react to a cosmetic applied to the face, a chemical on the hands, or an airborne allergen, all of which may appear as similar reactions.

Irritant contact dermatitis can produce a range of symptoms from mild redness to severe chapping to blisters and ulcerations on exposed areas. Most cases develop slowly, after repeated exposure to mild irritants. Harsh, irritating chemicals in high concentrations can cause dermatitis on anyone's skin.

Diagnosis

A careful medical history is the best tool for diagnosing contact dermatitis. Attention to recent and new as well as long-term exposures is important.

Patch testing may be performed when allergic contact dermatitis is suspected. During this procedure, various suspected and common allergy-inducing substances are taped to the patient's back for 48 hours. After removal, the individual areas are examined and any localized reactions are identified.

Treatment

Once offending chemicals or substances are identified, either by history or by patch testing, they can be eliminated. Afterward, the skin eventually heals on its own.

In addition to avoiding irritating or allergy-producing chemicals, treatment of contact dermatitis is directed toward symptom relief. Drying agents applied to blistered and weeping areas and moisturizers applied to chronic lesions that are thick and scaly often have an ameliorating effect.

The itch, at times severe, is best treated with topical corticosteroid creams. While this often suffices, severe and extensive involvement usually necessitates the use of systemic corticosteroids. Long-term use of corticosteroids is not recommended, however.

Prevention

Once the allergen that is causing allergic contact dermatitis is identified, it can be more easily avoided. When preservatives or fragrances are the culprits, the individual must learn to read the labels of creams and lotions to avoid exposure.

Strong, irritating chemicals can be replaced by less harsh equivalents. When exposure cannot be avoided in the workplace, contact with those chemicals can be minimized by wearing protective gloves and clothing. When there is no alternative, an affected individual may have to change his or her occupation or modify job responsibilities in order to avoid exposure.

Dermatitis (Eczema), Contact Dermatitis reprinted with permission from dermatologychannel.net
© 1998-2008 Healthcommunities.com, Inc. All Rights Reserved.

Dermatitis (Eczema) Resources

	Join Our Dermatitis (Eczema) Forum Do you have a question, want to share medical advice, or just need to discuss your situation with someone else having a similar experience? The healthchannels forum is a resource for everyone to share and discuss their health and medical needs with others.	Advertising Disclaimer
	Living with...Share your story Do you have a personal health story that you would like to share with others? As a source of free patient education, our goal is to provide our users with trustworthy information and support from others. That's why we've started our "Living with..." sections.
	Our "Living With..." support pages are a place to share experiences about living with a certain condition, disease, disorder, or illness and for loved ones of those dealing with health-related issues. Many people, especially when newly diagnosed, find comfort in knowing that others are having a similar experience. Help others by sharing your story. View stories already submitted.
	Stay Updated Sign up for our newsletter and receive important updates on the medical conditions that are most important to you.
Advertising Disclaimer To quickly access health information from your website's browser, download Healthcommunities.com's healthchannels toolbar. Advertising Disclaimer