What 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).
How common is contact dermatitis?
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.
Who might get contact 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:
- Construction workers.
- Food handlers.
- Healthcare providers.
- Janitors and plumbers.
What are the types of contact dermatitis?
The two main types of contact dermatitis are:
Allergic contact dermatitis: Your body has an allergic reaction to a substance (allergen) that it doesn’t 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.
Symptoms and Causes
What causes allergic contact dermatitis?
Every time your skin comes into contact with an allergen that it doesn’t like, your body’s 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:
What causes irritant contact dermatitis?
Irritant contact dermatitis occurs more often than allergic contact dermatitis. You develop a rash when a chemical substance irritates the skin’s outer layers. The rash is more painful than itchy.
Common causes of irritant contact dermatitis include:
- Alkalis like drain cleaners.
- Body fluids, including urine and saliva.
- Certain plants, such as poinsettias and peppers.
- Hair dyes.
- Nail polish remover or other solvents.
- Paints and varnishes.
- Harsh soaps or detergents.
- Resins, plastics and epoxies.
What are the symptoms of contact dermatitis?
Signs of contact dermatitis include a skin rash that is:
- Swollen, blistering or oozing.
- Burning or stinging.
- Flaky or scaling.
- Swollen or hive-like.
What should I do if I develop contact dermatitis on the job?
If you’re 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 what’s causing the rash.
Diagnosis and Tests
How is contact dermatitis diagnosed?
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. You’ll see your provider again in another 48-96 hours for one last skin check.
There isn’t a test for irritant contact dermatitis. Your healthcare provider may be able to determine what’s causing the rash based on the types of irritants or chemicals you’re exposed to regularly.
Management and Treatment
How is contact dermatitis managed or treated?
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:
- Avoidance: If you can figure out what’s causing the rash, take steps to avoid it or minimize exposure.
- Anti-itch creams: Corticosteroid creams can ease inflammation and itching.
- Oral steroids: Prednisone, a type of steroid, can relieve rash symptoms that don’t respond to antihistamines or other treatments.
- Immunosuppressive medications: In severe cases, where repeated bouts of oral steroids are needed.
What are the complications of contact dermatitis?
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. You’ll need an immediate epinephrine injection to counteract this allergic response. People with known allergies can carry an EpiPen®, a brand of injectable epinephrine.
How can I prevent contact dermatitis?
Avoiding known allergens and irritants is the best way to prevent contact dermatitis. But you can’t always stay away from every possible irritant. These steps can help:
- Choose fragrance-free moisturizers.
- Use mild, fragrance and dye-free soaps and cleansers.
- Wash immediately after coming into contact with a known allergen or irritant.
Outlook / Prognosis
What is the prognosis (outlook) for people with contact dermatitis?
If you’ve reacted to an allergen or irritant, you will continue to do so every time you’re 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.
When should I call the doctor?
You should call your healthcare provider if the skin rash:
- Goes away for a while and then returns.
- Looks infected (red, warm or swollen).
- Itches constantly.
- Doesn’t go away in a week with treatment.
What questions should I ask my doctor?
If you’re experiencing signs of contact dermatitis, talk to your healthcare provider. You may want to ask:
- Why do I have a skin rash (contact dermatitis)?
- Should I get an allergy test?
- What steps can I take to prevent contact dermatitis?
- What are the best treatments for contact dermatitis?
- What are the best treatments for a painful or itchy skin rash?
- What over-the-counter cleansers and moisturizers do you recommend?
- What signs of complications should I look out for?
Contact dermatitis is uncomfortable and can be painful or itchy. Talk to your healthcare provider about how you can find out what’s 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.