Irritant & Allergic Contact Dermatitis: Symptoms …

OverviewWhat is contact dermatitis?

Dermatitis is the medical term for skin inflammation (irritation). Contact dermatitis is an allergic or irritant reaction that causes a painful or itchy skin rash. As the name suggests, you get contact dermatitis from coming into contact with an allergen (like poison ivy) or an irritant (like a chemical).

The condition is common. We are surrounded by irritants and potential allergens. You might experience contact dermatitis more often if you have sensitive skin or other chronic skin problems like atopic dermatitis.

Irritant reactions can occur after a single exposure or after repeated exposures over time, whereas it takes multiple exposures to the same chemical to develop an allergy. People who work in certain professions have a higher risk of developing contact dermatitis. You might repeatedly encounter irritating chemicals or allergens in these professions:

The two main types of contact dermatitis are:

Allergic contact dermatitis: Your body has an allergic reaction to a substance (allergen) that it doesnt like. Common allergens include jewelry metals (like nickel), cosmetic products, fragrances and preservatives. It can take several days after exposure for an itchy, red rash to develop.

Irritant contact dermatitis: This painful rash tends to come on quickly in response to an irritating substance. Common irritants include detergents, soap, cleaners and acid.

Every time your skin comes into contact with an allergen that it doesnt like, your bodys immune system responds. White blood cells are recruited into the skin, releasing chemical mediators of inflammation. This response causes the itchy rash. The rash may appear minutes, hours or several days after exposure.

Poison ivy is a top cause of allergic contact dermatitis. Other causes include:

Irritant contact dermatitis occurs more often than allergic contact dermatitis. You develop a rash when a chemical substance irritates the skins outer layers. The rash is more painful than itchy.

Common causes of irritant contact dermatitis include:

Signs of contact dermatitis include a skin rash that is:

If youre regularly exposed to irritating chemicals or allergens at work and develop contact dermatitis, ask your employer for a chemical Safety Data Sheet. You can take this information to your healthcare provider to help determine whats causing the rash.

Clinical examination can reveal clues to the underlying diagnosis of irritant or allergic contact dermatitis. A careful history can uncover clues as to the offending agent.

With either type of contact dermatitis, you can avoid the substance for a while to see if the rash goes away. If avoidance is not possible or not sustainable, further diagnostic testing may be indicated.

For suspected cases of allergic contact dermatitis, a series of tests called patch testing can identify the underlying cause of allergic contact dermatitis.

With a patch test, you wear adhesive patches on your skin. The patches contain chemicals known to commonly trigger allergic reactions. After 48 hours, your healthcare provider checks your skin for reactions. Youll see your provider again in another 48-96 hours for one last skin check.

There isnt a test for irritant contact dermatitis. Your healthcare provider may be able to determine whats causing the rash based on the types of irritants or chemicals youre exposed to regularly.

Treatment for both types of contact dermatitis is the same. Even with treatment, it can take several weeks for the rash to go away. Treatments include:

Allergic contact dermatitis is a Type IV hypersensitivity reaction, caused by a different immunologic mechanism than hives, angioedema, or anaphylaxis. However, very rarely, patients may have immunologic dysfunction which results in multiple types of concurrent hypersensitivity reactions. Thus, it is possible that people with contact dermatitis can develop hives (urticaria) and swelling (angioedema) after coming into contact with an allergen. Hives are red, raised, itchy skin welts. Angioedema is swelling deep under the skin.

Extremely rare, allergic contact dermatitis can overlap with a severe, life-threatening allergic reaction called anaphylaxis that can swell airways and close them. If you think you are experiencing anaphylaxis, call 911. Youll need an immediate epinephrine injection to counteract this allergic response. People with known allergies can carry an EpiPen, a brand of injectable epinephrine.

Avoiding known allergens and irritants is the best way to prevent contact dermatitis. But you cant always stay away from every possible irritant. These steps can help:

If youve reacted to an allergen or irritant, you will continue to do so every time youre exposed to it again. You can prevent flare-ups by avoiding that substance.

Most people who have occupational contact dermatitis can find ways to reduce exposure so they can continue their work without breaking out in a rash.

You should call your healthcare provider if the skin rash:

If youre experiencing signs of contact dermatitis, talk to your healthcare provider. You may want to ask:

Contact dermatitis is uncomfortable and can be painful or itchy. Talk to your healthcare provider about how you can find out whats causing it, reduce your exposure and prevent reactions. You might develop contact dermatitis from working with irritants or chemicals. Ask your employer about how you can minimize rashes while remaining on the job.

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Irritant & Allergic Contact Dermatitis: Symptoms ...