Contact Dermatitis: Types, Symptoms, Causes, and Treatment
What is contact dermatitis? The simplest answer is contact dermatitis is a type of skin condition or reaction. It occurs when the skin encounters certain substances.
Contact dermatitis has two main causes:
- Allergens – substances that trigger an allergic reaction.
- Irritants – substances that cause irritation without an allergic reaction.
When an allergen or irritant touches your skin, it can damage the skin barrier. This can trigger inflammation of the skin. The reaction is often an itchy skin rash that can be painful. These symptoms may develop within minutes. But they can also take hours or even days to develop.
Contact dermatitis is very common skin condition. Anyone is at risk for developing contact dermatitis. An estimated 15-20% of people will experience contact dermatitis at some point in their lives.
Contact dermatitis is also the most common cause of work-related (occupational) skin conditions. Up to 95% of occupational skin conditions are from contact dermatitis.
Irritant contact dermatitis
Irritant contact dermatitis (or irritant dermatitis) is the most common form of contact dermatitis. It accounts for up to 80% of all cases of contact dermatitis.
Irritant contact dermatitis is normally caused by repeated exposure to an offending substance. This substance irritates the skin. Over time, that substance breaks down the skin barrier. This leads to more skin irritation and damaged skin cells.
People in certain occupations are at high risk for developing irritant contact dermatitis. They include workers in healthcare, agriculture, construction, hairdressing, and mechanics. These professions often put people in direct contact with irritants. If a substance is especially harsh, a single exposure could cause a quick reaction.
Some of the most common irritants include:
- Chemicals
- Textiles
- Insecticides
- Harsh soaps
- Bleach and detergents
- Cosmetics and skincare products
- Metals
- Wet diapers or pads
Even something as simple as soap and water can cause irritant contact dermatitis. This happens when frequent hand washing dries out the hands. This can break down the barrier.
Allergic contact dermatitis
Allergic contact dermatitis is a contact allergy. It occurs when the skin makes contact with an allergen. This triggers an immune system response. It causes a skin reaction, such as an itchy rash. This can develop from repeat exposures to the allergen.
Common allergens include:
- Plants such as poison ivy, poison oak and poison sumac. People encounter plants like poison ivy or poison oak when gardening, hiking, and doing outdoor activities. Just brushing across one these plants can trigger allergic contact dermatitis.
- Cosmetics, hair dyes, and skincare products. Products used on the skin and in hair dye may have ingredients that are allergens. These can include dyes, metals, fragrances, preservatives, and natural rubber. Any could potentially cause allergic contact dermatitis.
- Metals. Metals such as nickel, cobalt, chromium, and zinc are common triggers for allergic contact dermatitis. Nickel allergy is the most common cause of allergic contact dermatitis. These metals are found in jewelry and body piercings. They may also be found in tools, cosmetics, and many other household items.
- Fragrances. Fragrances used for perfumes and to provide scents to soaps, lotions and cosmetics can affect the skin. Fragrances are the second most common cause of allergic contact dermatitis.
- Preservatives. Preservatives such as formaldehyde and parabens are in lots of products. These include fabrics, baby products and cosmetics. They are common triggers for allergic contact dermatitis.
- Latex. Natural rubber latex is found in 40,000+ products, including many household items. They are also used in gloves and medical products. Exposure to latex can cause allergic contact dermatitis.
- Topical medications. Topical antibiotics such as neomycin and bacitracin are often used on skin. They are common triggers for allergic contact dermatitis.
You can have both irritant and allergic contact dermatitis. A board-certified allergist will be able to determine if your condition is from an allergen or irritant.
Contact dermatitis symptoms
Contact dermatitis symptoms typically involve a rash. But there are some distinctions between irritant and allergic contact dermatitis. If you have symptoms of a contact dermatitis rash, make an appointment with a doctor.
Symptoms of irritant contact dermatitis
With irritant contact dermatitis, symptoms are often found on the hands. They are often symmetrical with clear borders. Normally, the rash does not spread.
Symptoms of irritant contact dermatitis include:
- Itchy rash
- Painful skin irritation
- Swelling
- Red patches on light skin, brown or purplish patches on dark skin.
- Blisters or pustules (pus filled pockets of skin)
- Broken blood vessels in the skin (called hemorrhage)
- Crusty skin
- Scaly skin
- Skin breakdown
Symptoms of allergic contact dermatitis
With allergic contact dermatitis, symptoms are often found on the back of hands or forearms. Often the rash is asymmetrical without clear borders. It may start in one area but spread to another. Let’s say your hands touch some poison ivy. You may get a rash on the hand that touched it. But then maybe you rub your face or mouth. That’s how the rash spreads.
Symptoms of allergic contact dermatitis include:
- Very noticeable itchy rash
- Red or darkened skin patches
- Scaly skin
- Dry skin
- Leathery skin
- Cracks in skin
- Skin shedding
Allergic contact dermatitis symptoms often appear in phases instead of all at once. Leathery, cracked, itchy skin is more consistent with allergic reactions.
How is irritant or allergic contact dermatitis diagnosed?
Skin problems can be hard to diagnose. If you think you have a contact dermatitis rash, make an appointment with a healthcare provider. An allergist or dermatologist will be able to make the diagnosis.
There is no specific test or procedure to confirm a diagnosis of contact dermatitis. Your healthcare provider will take your medical history and perform a physical exam. Some questions to expect:
- When did your symptoms start?
- Have you started using any new products at home?
- Have you started wearing new jewelry?
- What do you do for work?
- Are you routinely exposed to any harsh soaps or irritating chemicals?
You may want to come to an appointment with a doctor with a list of any new soaps, detergents, skincare or cleaning products you are using.
If there is concern about a potential workplace exposure, let your doctor know. Come to the appointment with a list of potential substances that you’re around at work.
If you suspect you have allergic dermatitis, your doctor may recommend a procedure called patch testing. A patch test involves placing a patch containing allergens on your skin. The patch stays on your skin for 48 hours. Your doctor will look for signs of an allergic reaction where the patch was placed. If an allergen is identified, you are diagnosed with allergic contact dermatitis.
If your doctor suspects other causes for your skin reaction, you may need to undergo further testing. Some of the tests will be to rule out other skin diseases or infections.
Treatment options for contact dermatitis
How is irritant or allergic contact dermatitis treated? Treatment focuses on managing and reducing symptoms. This gives the skin time to heal. Treatment also aims to reverse any skin damage.
Contact dermatitis involves different healing stages. Some treatments are needed for certain stages. Work with your healthcare provider to determine the right treatment for your symptoms.
Contact dermatitis treatment includes:
Over the counter (OTC) treatments
- Burrow’s solution, calamine lotion, or oatmeal baths for oozing phase
- Cold compresses for itchy rash
- Antihistamines to help with sleep
- OTC topical corticosteroids – hydrocortisone cream
Prescription treatments
- Prescription topical steroids (for when a stronger medication is needed than OTC hydrocortisone)
- Oral or intravenous corticosteroids – usually given in a short course or burst for severe cases
- Topical immunomodulators – anti-inflammatory medications, may include tacrolimus or pimecrolmus
If your treatment is not working, your doctor may recommend phototherapy. This is an in-office procedure to expose affected skin to ultraviolet light. It provides relief from itching and swelling and allows the skin time to heal. Phototherapy is a second-line treatment for skin conditions. It is only recommended when other treatments have not worked.
As the skin heals, talk to your healthcare provider about moisturizing your skin regularly. Prevention is key. More irritant contact dermatitis or allergic contact dermatitis may occur in the future. Also ask for advice on being skin-safe when outdoors in the sun.
What if my contact dermatitis becomes infected?
Contact dermatitis can become infected if you constantly scratch the affected area. This opens up the skin and allows bacteria or fungi to grow.
Symptoms of contact dermatitis infection may include:
- increased pain on the affected area
- an oozing discharge from the skin
- you feel hot or you have the shivers
Contact dermatitis can turn severe with an infection. Schedule an appointment with a doctor. In addition to over-the-counter and prescription medications, your doctor may give you pills such as antibiotics to help fight the infection.
Tips for preventing contact dermatitis.
- Try your best to avoid scratching affected skin. This will prevent contact dermatitis from worsening. If you must scratch, try stroking the itchy area using the top side of your hand instead of your fingernails.
- Identify allergens and irritants and develop strategies to avoid contact with them.
- Avoid excessive handwashing.
- Use mild, fragrance-free soaps, detergents and cleansers.
- Use soft, non-scratching cloths on the skin.
- Ensure that clothes and other items made of leather, cotton, or other materials are soft and don’t irritate the skin.
- Avoid tight-fitting clothes.
- Don’t use belt buckles with metal or wear jewelry if you’re allergic to nickel.
- See a doctor if a rash doesn’t improve after trying home remedies.
Questions & Answers (Q&A) on Contact Dermatitis
You may have specific questions about irritant and allergic contact dermatitis. Here’s a Q&A with some common questions about this condition. If there’s a topic you’d like to see answered in this Q&A, please email Gary Fitzgerald, Senior Editor.
Reviewed by:
William E. Berger, MD, FACAAI, is a board-certified allergist and immunologist who serves as Medical Director with Allergy & Asthma Network. He is a Distinguished Fellow and Past President (2002-03) of the American College of Allergy, Asthma & Immunology (ACAAI).