Everything You Need to Know About Contact Dermatitis, by Dermatologists
Authors: Gun Ho Lee, MD and David G. Li, MD, MBA
Gun Ho Lee is a resident at the Harvard Medical School Combined Dermatology Program. His clinical interest includes patch testing for allergic contact dermatitis. His practice after graduating will be focused on caring for those with allergic contact dermatitis in addition to other dermatological conditions.
David Li is a board-certified dermatologist in private practice in downtown Boston and the Founder of BDA. Previously he was a resident at the Harvard Medical School Combined Dermatology Program.
Table of Contents
What Exactly is Contact Dermatitis?
What Causes Contact Dermatitis to Develop?
What are Common Symptoms of Contact Dermatitis?
Who is at Risk for Developing Contact Dermatitis?
When to See a Dermatologist About Contact Dermatitis
How is Contact Dermatitis Diagnosed?
How Can Contact Dermatitis Be Treated?
Tips and Products for Preventing Future Contact Dermatitis
Contact dermatitis is an itchy rash that develops after the skin comes into contact with an allergen or irritant. It's one of the most common diagnoses made by dermatologists and can affect people of any age.
If you think you may be experiencing symptoms of contact dermatitis, understanding the causes, signs to look for, and treatment options can help.
In this article, our team of board-certified dermatologists and dermatology residents will attempt to cover everything you would need to know about contact dermatitis, especially if you suspect yourself as having this condition or have been diagnosed with contact dermatitis.
What Exactly is Contact Dermatitis?
Contact dermatitis refers to inflammation of the skin resulting from contact with a substance that causes an allergic or irritant reaction. There are a few types of contact dermatitis:
Allergic contact dermatitis occurs when the skin develops an allergic response upon contact with a normally harmless substance like nickel, fragrance, or certain chemicals in plants.
Irritant contact dermatitis develops as a result of contact with irritating substances like acids, detergents, or solvents that damage the skin directly.
Other less common forms include contact urticaria, photoallergic dermatitis, and systemic contact dermatitis.
Regardless of exact type, contact dermatitis is characterized by a red, blistering, oozing, itchy rash that can appear anywhere on the body. It’s one of the most frequently diagnosed skin conditions by dermatologists.
What Causes Contact Dermatitis to Develop?
Contact dermatitis always occurs after coming into contact with an external substance that either causes an allergic reaction or physically irritates the skin.
Common causes and sources of contact allergens include:
Metals like nickel and cobalt are often found in jewelry, snaps and fasteners on clothing, watches, keys, coins, etc. Nickel is the most common contact allergen that we test for.
Plants such as poison ivy, poison oak, poison sumac, mango skin, cashew tree, ginkgo biloba
Topical medicines, creams or ointments (triple antibiotic ointment is a common culprit)
Fragrances
Preservatives
Rubber chemicals (thiurams, carbamates)
Hair dyes and tattoos (including temporary henna tattoos)
Adhesives and glues, such as those found in skin glue, adhesive bandages, and most nail products
Leather tanning chemicals
Irritant contact dermatitis frequently occurs as result of contact with:
Acids and alkalis
Solvents and chemicals
Soaps and detergents
Mechanical trauma from friction
Heat, cold weather
Water overexposure
Plants such as daffodils, buttercups, pineapple, hot peppers
Exposure to these irritants or allergens prompts the body’s immune system to trigger swelling, redness and itching. The rash can develop either immediately or several days later depending on the substance and whether it’s an allergen or irritant.
What are Common Symptoms of Contact Dermatitis?
The most prominent sign of contact dermatitis is a red, itchy rash at the site of contact with the provoking substance which can blister in severe reactions. Though symptoms may vary depending on whether it’s irritant vs. allergic, possible signs include:
Red, cracked, flaking, blistered, scaly skin
Intense itching and burning
Rash, bumps or blisters filled with fluid
Swelling, dryness, peeling around site
Oozing clear fluid or crusting lesions
Pain or tenderness
Changes in skin color like light spots/discoloration
Severe reactions can cover large body surface areas, especially on the hands, face, neck and skin folds. See your doctor promptly if you experience any unusual skin changes after using a new product.
Who is at Risk for Developing Contact Dermatitis?
Anyone can develop contact dermatitis when their skin is exposed to an irritant or allergen. It is possible for your body to develop an allergic reaction to a product you have previously used without symptoms. Those at increased risk include people with:
Atopic dermatitis or other chronic skin condition
Occupations involving frequent wet work or chemical handling
Prior reaction to certain metals, fragrances or topical products
When to See a Dermatologist About Contact Dermatitis
It’s important to make a timely dermatologist appointment if you suspect contact dermatitis for proper diagnosis and treatment. Signs it’s time to seek medical care include:
Itching, rash/bumps not improving after a few days
Severe swelling, blistering and oozing
Rash spreading to larger body surface areas
Symptoms interfering with sleep or daily functioning
Experiencing fever, fatigue or flu symptoms along with rash
Left untreated, some cases of contact dermatitis worsen progressively and take longer to heal. Early dermatologist intervention can improve outcomes.
How is Contact Dermatitis Diagnosed?
Making an accurate contact dermatitis diagnosis involves:
Medical history – The dermatologist will inquire about any new products, plants, metals or substances you were exposed to prior to rash onset. Details help pinpoint the source.
Physical exam - They’ll thoroughly evaluate all current rash characteristics and check body locations affected.
Skin biopsy (sometimes) – A small sample of rash tissue gets analyzed under a microscope to rule out other conditions which can mimic contact dermatitis.
Once the dermatologist determines the provoking allergen or irritant behind your contact dermatitis, they’ll provide guidance to avoid future exposure along with proper treatment recommendations.
Your dermatologist may recommend more specific tests to identify potential skin allergies you may have. The gold standard for diagnosing allergic contact dermatitis is patch testing, which is a week-long process performed at a dermatologist’s office. Multiple allergen patches are applied to the skin for 48 hours, followed by 1-3 assessments to identify reactions to specific allergens. Patch testing is different from intradermal or “skin prick tests”, which are short (less than 1 hour) procedures performed by an allergist examining environmental allergens such as dust mites and pollen. Not every dermatologist performs patch testing, but they will be able to refer you to someone who does.
How Can Contact Dermatitis Be Treated?
A dermatologist tailors contact dermatitis treatment based on reaction severity and type. For instance, irritant CD may differ from allergic CD in terms of treatment, which can involve:
Avoiding triggers – This is first line and most important. For irritant reactions, this means avoiding use of triggering products. For allergic contact dermatitis, this requires avoiding contact with the problematic metal, chemical or plant.
Some allergens are difficult to avoid. If you receive patch testing, your dermatologist will be able to provide you a “safe list” of products that avoid the ingredients that you are allergic to. The most common databases that are used are CAMP (Contact Allergen Management Program) and SkinSAFE.
Wet wraps - Wet bandages covered by dry ones help soothe itch and hasten healing.
Topical corticosteroids – These prescription anti-inflammatory creams or ointments like triamcinolone or desoximetasone provide relief from swelling, redness and itch when applied to affected areas.
Oral antihistamines – Some patients find relief by using medications like cetirizine or fexofenadine, and this is the treatment of choice for certain allergic reactions such as seasonal allergies or contact urticaria (a rare type of skin reaction to allergens such as latex). However, true allergic contact dermatitis does not involve histamines, so these antihistamine drugs would have minimal effect.
Antibiotics (if infected) – Bacterial skin infections may require oral antibiotics or antibiotic ointments.
Phototherapy – For severe refractory cases, targeted UV light treatment helps resolve residual inflammation and itching.
Identifying and avoiding contact allergens or irritants is critical for preventing recurrent flare-ups of contact dermatitis. See your dermatologist promptly whenever a new rash appears so proper treatment can begin right away.
Tips and Products for Preventing Future Contact Dermatitis
Once you know what substances provoke your contact dermatitis, the most vital thing is trying to avoid future exposure. Helpful prevention tips include:
✔️ Wear gloves when doing housework or yardwork involving handling irritants
✔️ Use fragrance-free, dye-free skincare and laundry products
✔️ Apply cream or ointment-based moisturizer daily to protect skin’s moisture barrier
✔️ When trying new products, test by applying first to small area and watch for reactions
See your dermatologist right away whenever you experience new unexplained rashes so they can determine if it’s contact dermatitis and guide proper treatment. Identifying triggers early prevents unnecessary discomfort and lasting skin damage from scratching or infections. Although there is no way to prevent developing a new skin allergy, most contact dermatitis cases can be effectively managed long term.
Recommended Products for Those with Suspected Contact Dermatitis
Fragrance Free Moisturizer
Free & Clear Shower Package
Key Takeaways on Contact Dermatitis
Contact dermatitis stems from skin contact with external allergens or irritants
Common triggers include metals, plants, fragrances and harsh ingredients
Signs involve a red, oozing itchy rash at contact site
See a dermatologist promptly for diagnosis and patch testing
Treatment focuses on avoiding triggers and using topical steroids
Prevent recurrent cases by avoiding future exposure to problematic allergens or irritants
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What is eczema and how does it differ from contact dermatitis?
Eczema refers to a group of conditions that cause itchy skin, inflammation, and irritation. Most commonly, it refers to atopic dermatitis, which is a multifactorial, intrinsic condition that typically starts in infancy. In contrast, contact dermatitis is caused by the body’s reaction to an external allergen or irritant.
What are the common causes of allergic contact dermatitis?
The common causes of allergic contact dermatitis include nickel, fragrances, preservatives, and rubber products.
How is occupational contact dermatitis diagnosed?
Occupational contact dermatitis is diagnosed through a thorough examination of the affected skin, a review of the patient's medical history, and potentially, patch testing to identify specific allergens or irritants. If you suspect you may be experiencing a workplace-related allergen or irritant, it is helpful to bring to your dermatologist a written list of products you come into contact with at work.
What are the signs and symptoms of contact dermatitis?
The signs and symptoms of contact dermatitis may include redness, itching, swelling, and blisters at the site of contact. It can vary from mild to severe.
How can contact dermatitis be prevented?
To prevent contact dermatitis, it's important to identify and avoid the triggers. This can involve avoiding specific substances, using protective clothing, and implementing good skincare practices.
What is the difference between contact allergy and irritant contact dermatitis?
Contact allergy is a specific immune response to an allergen, while irritant contact dermatitis may result from direct damage to the skin barrier caused by an irritant substance.
How is contact dermatitis treated?
Treatment for contact dermatitis may involve topical corticosteroids, emollients, and in severe cases, oral medications. It's crucial to identify and avoid the trigger, as well as manage the symptoms.
What is balsam of Peru and its association with allergic contact dermatitis?
Balsam of Peru refers to sap from the Myroxylon pereirae tree, which grows in El Salvador. It is a complex mixture of fragrance chemicals which can be found in personal care and household products. Certain foods naturally contain a subset of the same chemicals found in Balsam of Peru, and a very small minority of patients find that they develop contact dermatitis when they eat these food items. We do not recommend any restrictive diets prior to consultation with your primary care doctor or dermatologist.
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We are a group of dermatology residents and attending physicians based in Boston, MA. Our team of Ivy League-trained dermatologists is demystifying the cosmeceutical industry by offering unbiased, scientifically supported reviews of skincare products. We are extremely passionate about skincare and making it accessible to all through education. We value integrity, practicality, and inclusivity. No sponsorships were received for the products prior to testing; we feel strongly about providing un-biased reviews. After blogs are published, following the links in this blog post may result in commission.
