What is contact dermatitis?
Contact dermatitis is a type of skin rash. It occurs when skin comes into contact with 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 2 types of contact dermatitis:
- Allergic contact dermatitis. This occurs when skin, which has become sensitive 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. This occurs when the skin is repeatedly exposed to a mild irritant (such as detergent or solvents) over a long period of time. If skin is exposed to a strong irritant (such as acid, alkali, solvent, strong soap, or detergent), skin damage can be immediate.
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. Examples of these include dental workers, healthcare workers, florists, hairdressers, and machinists.
What are common sources of allergic contact dermatitis?
Not everyone reacts to allergens. However, some people become allergic to something that they had previously tolerated for many years. Skin can become allergic to a substance after many exposures or after just 1 exposure. Common sources of allergic contact dermatitis include:
- Metals such as nickel (present in costume jewelry or snaps on jeans). Nickel may cause an allergic dermatitis in areas in contact with the metal (for example, the ears under earrings). Gold is also becoming a widespread allergen.
- Fragrances, such as those found in perfumes, soaps, lotions, and shampoos.
- Topical medications, such as antibiotics (Neosporin®) or anti-itch preparations. These may cause an allergic reaction or even worsening of the initial problem and are often misdiagnosed as an infection.
- Preservatives. These substances keep topical products from spoiling.
- Sunscreens. These commonly cause a hive-like rash that can appear hours or days after sun exposure.
- Rubber ingredients. Rubber is a common source of work-related allergies. It can cause immediate allergic reactions, such as itching, burning, or welts. Some people experience itching and tearing eyes or even shortness of breath.
What are 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 cleaning products.
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 include:
- 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)
- Sun sensitivity
- Darkened, "leathery," and cracked skin
Allergic contact dermatitis can be very difficult to distinguish from other rashes.
Irritant contact dermatitis symptoms include:
- Mild swelling of skin
- Stiff, tight feeling skin
- Dry, cracking skin
- Painful ulcers on the skin
Symptoms vary depending on the cause of dermatitis.