What is contact dermatitis?
Contact dermatitis is inflammation of the skin (rash) that
may result when the skin is touched by chemicals or physical substances that
cause an allergic or irritant reaction. Contact dermatitis can occur from
exposure to many different compounds found both in the home and at work. There
are two types of contact dermatitis:
- Allergic contact dermatitis -- occurs when skin,
which has become sensitized to a certain substance (allergen), comes in
contact with that substance again. This is a delayed skin reaction that
typically develops 12 to 72 hours after exposure.
- Irritant contact dermatitis -- occurs when
the skin is exposed to a mild irritant (such as detergent or solvents)
repeatedly over a long period of time or a strong irritant (such as
acid, alkali, solvent, strong soap or detergent), which can cause
immediate skin damage.
Common sources of allergic contact dermatitis
Not everyone reacts to allergens. However, some people will
react to an allergen which they had previously tolerated for many years. Skin
can become allergic to a substance after many exposures or after just one
exposure. Most people will have an allergic reaction to poison ivy after one
exposure, for instance. Common sources of allergic contact dermatitis include:
- Metals, such as nickel (present in costume jewelry, snaps on jeans,
buckles on belts, etc.) may elicit an allergic dermatitis in areas in
contact with the metal (for example, the ears under earrings). Gold is also
becoming a widespread allergen.
- Fragrances, for example, those found in perfumes, soaps, lotions, and shampoos
- Cosmetics
- Topical medications, such as antibiotics (Neosporin®, for example) or anti-itch preparations, may cause an allergic reaction
or even worsening of the initial problem and are often misinterpreted as infection
- Preservatives, which keep topical products from spoiling
- Sunscreens commonly cause a hive-like rash that can appear hours or days
after sun exposure
- Rubber ingredients, a common source of work-related allergy. Rubber can
cause immediate allergic reactions, such as itching, burning, or welts. Some
people experience itching and tearing eyes or even shortness of breath.
Common sources of irritant contact dermatitis
Detergents, soaps, cleaners, waxes, and chemicals are
substances that can irritate the skin. They can wear down the oily, protective
layer on skin surface and lead to irritant contact dermatitis. Irritant contact
dermatitis is common among people who regularly work with strong chemicals or
detergents, such as restaurant, maintenance, and chemical workers. It is also
seen in people who do a lot of housework due to contact with cleansing products, etc.
Are certain occupations at greater risk?
Some occupations have more exposure to chemicals or
substances that can result in sensitization and cause allergic contact
dermatitis. These include dental workers, health care workers, florists,
hairdressers, machinists, and photographers among many others.
What are the symptoms of contact dermatitis?
Contact dermatitis symptoms can range from mild redness and
dryness to severe pain and peeling that can be disabling.
Allergic contact dermatitis symptoms:
- Reddening of skin (either in patches or all over the body)
- Intermittent dry, scaly patches of skin
- Blisters that ooze
- Burning or itching that is usually intense without visible skin sores (lesions)
- Swelling in the eyes, face, and genital areas (severe cases)
- Hives
- Sun sensitivity
- Darkened, "leathery," and cracked skin
Allergic contact dermatitis can be very difficult to distinguish from other rashes.
Irritant contact dermatitis:
- Mild swelling of skin
- Stiff, tight feeling skin
- Dry, cracking skin
- Blisters
- Painful ulcers on the skin
Symptoms vary depending on the cause of dermatitis.
How can I know if I have contact dermatitis?
If you have a skin rash that won't go away, visit your
health care provider. If he or she suspects allergic contact dermatitis, patch
testing may be performed. In this test, small samples of chemicals are placed on
an area of skin on your back to see if a rash develops. There are no needles or
pricking of the skin. These areas of the skin are then evaluated after 48 hours
and again at 96 hours or one week.
The advantage of patch testing is that, if you are allergic to
any chemical/product, the allergens can be identified, and your health care
provider can effectively treat the rash with therapy and avoidance of the
allergen(s). There are no tests that can be done for irritant contact
dermatitis. Tell your health care provider about any irritating substances or
chemicals that you regularly come into contact with (including cosmetics,
lotions, and nail polish).
With either type of contact dermatitis, you can avoid substances
you suspect and see if the rash improves.
How is contact dermatitis treated?
The form of treatment will depend on the cause of contact
dermatitis. Common treatments include: oral and/or topical corticosteroids
antihistamines, lotions and creams or oatmeal baths (to relieve itching).
How can I prevent contact dermatitis?
For allergic contact dermatitis:
- Avoid contact with substances that cause the skin rash.
- Wash any area that comes into contact with allergic substances.
- Learn to recognize poison oak and poison ivy.
For irritant contact dermatitis:
- Wear cotton gloves under rubber gloves for all wet work. Or, use
petroleum jelly to protect the skin. Reapply the petroleum jelly two or
three times a day and after washing your hands.
- Avoid contact with substances that irritate the skin.
- Use mild soaps.
- Use hand creams and lotions frequently.
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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 11/6/2009...#6173
