How to treat contact dermatitis

Causes | Symptoms | Diagnosis | Contact dermatitis treatment | Prevention

It started as an itchy red rash at one corner of my upper eyelid and spread from there to cover my entire face and chest. It felt like a really bad sunburn, that peeled two or three times a day. It itched like crazy, as the dead skin cracked and flaked away to make room for the dying skin beneath it. I tried using moisturizing creams and lotions to treat the redness and inflammation. Though I had no history of allergies, I had developed contact dermatitis.

If you’ve ever had a reaction to poison ivy or poison sumac, you know what contact dermatitis, or contact eczema, is: patches of skin that are red, irritated, blistered, and itchy where your skin came into contact with the leaves. It occurs because your body had an allergic reaction to a substance in the poison ivy. Typically, the reaction will subside within a couple of weeks. But with some cases of contact dermatitis, the cause isn’t so clear-cut, and the itchy rash can go on for months and affect your quality of life. Those cases may require a more thorough diagnosis and stronger medication, but most of the time you can work with your healthcare provider to find an effective contact dermatitis treatment.

Causes

Contact dermatitis happens when skin comes into contact with something that either irritates it (irritant contact dermatitis) or triggers an allergic reaction (allergic contact dermatitis). Irritant dermatitis is far more common, accounting for 80% of all contact dermatitis cases, according to the National Eczema Association. Diaper rash, which affects up to 35% of infants at some point, is a type of irritant dermatitis caused by contact with soiled diapers.

Other common irritants that can damage the outer layer of skin and cause a rash include:

• Rubbing alcohol
• Bleach, detergents, and fabric softeners
• Solvents, such as nail polish remover
• Soaps, shampoos, cosmetics, skin and hair-care products
• Acids or chemicals
• Plants
• Fertilizers and pesticides
• Topical antibiotic ointments or creams
• Essential oils

Allergic contact dermatitis accounts for about 20% of all contact dermatitis cases. It typically happens when skin comes into contact with an allergen, a substance to which the skin has a sensitivity. In rare cases, the allergen can enter the body through food, medicine, or a dental procedure. This is called systemic contact dermatitis. The allergen triggers your body’s immune system to respond, and your immune system’s response is to cause the dermatitis. 

“Contact allergies are delayed hypersensitivity reactions that cause a rash,” says Cory Dunnick, MD, a dermatologist, professor, and director of clinical trials in the University of Colorado department of dermatology. “The rash represents inflammation in the skin. The antigen-presenting cells (Langerhans cells) recruit T cells, which release cytokines (proteins that affect the interactions between cells), causing inflammation in the skin that came in contact with the allergen.”

Roughly 3,000 chemicals are known to cause allergic contact dermatitis. The most common one is nickel, which is frequently found in jewelry and belt buckles. Other common allergens are often found in:

• Medications, including oral antihistamines and antibiotic creams/ointments
• Deodorants or antiperspirants, especially those containing aluminum, fragrances, preservatives, or dyes
• Body washes, shampoos, and hair dyes
• Cosmetics, perfume, and nail polish
• Pollen
• Textiles
• Insecticides
• Formaldehyde
• Poison ivy, poison sumac, mango, and other plants containing a substance called urushiol
• Products like sunscreens and oral medications that can cause a reaction when you’re in the sun (photoallergic contact dermatitis)
• Diaper rash creams and ointments because they commonly contain zinc

Symptoms

In most cases, symptoms of contact dermatitis appear within hours of exposure to the irritant or allergen, although some allergens may take a day or two to cause a reaction. With irritant dermatitis, the symptoms are usually limited to the skin that made direct contact with the irritant, whereas allergic contact dermatitis can start with a small patch or patches and spread to cover a wider area.

Symptoms of contact dermatitis include:

• Red rash or red bumps across the affected area
• Burning sensation
• Tenderness
• Itching that can be severe
• Skin that cracks, peels, or flakes
• Blisters that may ooze and crust over

In chronic cases of contact dermatitis, the skin may harden and start to form plaques. For that reason, contact dermatitis can resemble psoriasis, atopic dermatitis, and other types of eczema.

Most contact dermatitis cases are physically harmless and non-life-threatening, but in severe cases hospitalization may be required, and the condition can have a sizable negative impact on one’s quality of life and mental health. For example, scratching may introduce other bacteria or viruses that result in superinfections. In my case, my eyelids would crack and crust over so badly that I could barely see in the morning until I’d taken a shower and scrubbed away all the dead skin. The condition also made it difficult to focus on work or daily activities.

RELATED: Psoriasis vs. eczema vs. dry skin

Diagnosis

In most cases of contact dermatitis, once the allergen or irritant is no longer near your skin, your symptoms should go away within about three weeks. See a doctor if your symptoms go on longer than three weeks or if the rash spreads quickly or becomes so uncomfortable that it affects your sleep or daily activities. You should also see a doctor if the rash affects your genitals, mouth, or eyelids, where your skin is thinner and can be damaged more easily.

To diagnose a case of contact dermatitis, your provider will examine the rash and ask you questions about your work environment, hobbies, the cleansing and cosmetic products you use, your exposure to nickel and other metals, and other things that might hint at what is triggering your allergic reaction. A doctor may also remove a tiny sample of skin for a biopsy that can confirm the diagnosis.

To determine the specific allergens to which patients are allergic, doctors frequently do a patch test. Patch testing involves adhesive patches that have small, diluted amounts of common allergens applied to them. The doctor places the patches on the patient’s back for two days and then checks after day three and day four to see which allergens, if any, caused a reaction in the patient’s skin. If the results are inconclusive, the doctor may call for further testing.

My patch test determined that I was allergic to nickel, a compound called Cl+Me-isothiazolinone, and another compound called colophony. Cl+Me-isothiazolinone is a common ingredient in body washes, shampoos, paint, and yard care products. Colophony, a rosin that comes from the sap of coniferous trees, is commonly found in wood and sawdust, paints, stains, lacquers, glues, solvents, and numerous other products sold in the hardware store where I worked.

Treatment

The first step in treating contact dermatitis is avoiding the irritant or allergen that caused the rash. With something like poison ivy or poison oak, this can be easy to do, but in many cases of allergic contact dermatitis, steering clear of allergens can be difficult. For me, treatment meant I had to get a plastic belt buckle, quit my job at the hardware store, and start reading ingredient lists on any soap, lotion, shampoo, detergent, or other household product that comes into contact with my skin. For people allergic to things like pollen and dust, it can be almost impossible to stay allergen-free.

In most cases of contact dermatitis, once the irritant or allergen has been identified and avoided, the rash resolves within two to four weeks without further treatment. While the rash is healing, you can ease the discomfort with the following home remedies, including:

• Applying anti-itch cream or calamine lotion to the affected area
• Avoiding scratching—applying cool compresses to the skin can help with the itching
• Cut and clean under fingernails
• Soaking in a lukewarm bath with oatmeal or baking soda added to the water
• Applying hydrocortisone cream, which can help reduce redness and swelling in the skin
• Taking an oral antihistamine such as Benadryl Itch Relief (diphenhydramine), Zyrtec (cetirizine), or Claritin (loratadine) to help control the itching

For more severe cases of contact dermatitis or cases that don’t resolve on their own, healthcare providers will often prescribe topical corticosteroids or immunosuppressive medications.Treatment options include:

• Protopic (tacrolimus), a topical calcineurin inhibitor that weakens the immune system and decreases the body’s allergic reaction
• Elidel (pimecrolimus), a topical calcineurin inhibitor that suppresses the immune system and decreases the body’s allergic reaction
• Eucrisa (crisaborole), a nonsteroidal cream that reduces inflammation, itchiness, and redness
• Cellcept (mycophenolate mofetil), an oral immunosuppressant that helps decrease the immune response that causes dermatitis
• Sandimmune (cyclosporine), a calcineurin inhibitor administered orally or by injection that weakens the immune system and helps decrease the immune response that causes dermatitis
• Vistaril (hydroxyzine pamoate), an oral antihistamine that blocks histamines that cause an allergic reaction and helps control itching

For rashes that don’t respond to the above treatments, doctors may also prescribe a program of light therapy, or phototherapy, which uses different wavelengths of ultraviolet light to help reduce itching and inflammation.

Prevention

The main way to prevent contact dermatitis is to identify the irritants or allergens that cause your skin to break out in a rash and avoid those substances. This isn’t always easy to do, depending on what you’re allergic to. Other steps you can take to help prevent flare-ups include:

• Wash your skin thoroughly immediately after coming into contact with an irritant or allergen
• Wear protective clothing, including longs sleeves and pants, protective eyewear,  gloves, or a face mask, when you have to be around substances that might cause an allergic reaction
• Cover up metal fasteners in your clothing that might irritate your skin
• Apply moisturizing creams or lotions regularly
• Check the ingredients in your shampoos, soaps, and other household products, and use only ones that are free of your known allergens

“The key is to eliminate any possible causes,” says Clare Foss, MD, a dermatologist with Glenwood Medical Associates in Colorado. “Fragrance is one of the most common things, so use soap that doesn’t have any added fragrances. Use laundry detergent that’s free of fragrance or dyes, and make sure to keep your skin moisturized. That can help prevent the skin from drying out and getting irritated.” Also, you can double rinse laundry to remove any incidental fragrances or chemicals. 

By avoiding irritants and allergens, dealing with rashes promptly, and taking other preventative steps, most people can effectively treat contact dermatitis and keep it from upending their lives.