Eczema types: Contact dermatitis diagnosis and treatment

By gathering the right information and studying it, dermatologists have found causes of contact dermatitis that often surprise their patients. Examples include:

• Cleaning supplies used to clean the toilet seats at a patient’s workplace

• Incense that a patient’s roommate burns

• Wedding ring that a patient has worn for more than a decade

How do dermatologists diagnose contact dermatitis?

When a dermatologist suspects that contact dermatitis is causing your rash, a dermatologist will:

• Examine your rash(es) carefully

• Ask you questions about your health, job, hobbies, and everyday activities, when necessary

• Test your skin to see if you are allergic to anything that may cause a rash, when necessary

The questions that your dermatologist asks can play a key role in finding out if you have contact dermatitis. For this reason, it’s important to think carefully about your answers.

When talking with your dermatologist be sure to mention:

• All the skin, hair, and nail care products you use

• Whether you apply skin, hair, or nail care products to someone you care for, such as a child or an elderly parent

• When the rash appears

Your dermatologist may ask for details about your work. Many people develop contact dermatitis at their workplace. This is a common problem for hairstylists, health care workers, florists, chefs and other food service workers, people who work in manufacturing or agriculture, and mechanics.

After examining your skin and listening to your answers, your dermatologist may be able to figure out what is likely causing your rash. For example, your dermatologist can often quickly tell if poison ivy or an e-cigarette is the cause. To the trained eye, both leave telltale signs.

If an ingredient in your skin care products is causing your rash, it can be difficult to know which ingredient is responsible. Your dermatologist may have you stop using certain products for a while to see if the rash clears.

Sometimes, your dermatologist will recommend patch testing.

Finding the cause of contact dermatitis often requires a detective-like approach

So many things that touch your skin can lead to contact dermatitis.

How do dermatologists treat contact dermatitis?

The best way to treat contact dermatitis is to avoid what’s causing it. If you can avoid the cause, the rash and symptoms will go away.

Once you know what’s causing your contact dermatitis, learning what to avoid can be straightforward. For example, if poison ivy caused your rash, avoiding plants that contain urushiol (what causes the allergic reaction) can prevent another rash. When you cannot avoid these plants, your dermatologist can teach you how to protect your skin.

Other times, avoiding what causes your contact dermatitis can be more difficult. For example, if you’re allergic to nickel, hundreds of things that touch your skin could cause a rash. Everyday objects that may contain nickel include cell phones, buttons and zippers on clothing, and jewelry.

Your dermatologist can help you develop a realistic plan for avoiding what causes your rash. Learning what to do may take time. Taking the time to learn what can cause your rash will help you feel more comfortable and develop fewer rashes.

Because so many things can irritate the skin or cause an allergic reaction, it’s not always possible to find the cause. To complicate matters, some people develop allergies to many different things. When this happens, treatment can help.

Medication and other treatments for contact dermatitis

To relieve your discomfort and help clear the rash, your dermatologist may include one or more of the following in your treatment plan.

Rash: Medication prescribed by your dermatologist that you apply to the rash.

Rash that covers much of your skin: Medication that works throughout your body, such as prednisone. This medication can reduce the swelling and clear the rash. Most people get relief within 12 to 24 hours.

Itch relief: Cool compresses. Your dermatologist will explain how to use these.

Open sores that leak: Calamine lotion or colloidal oatmeal baths

Follow the directions that come with your medication

Some people are tempted to quit a medication when they see the rash clear. This can cause a serious problem. If you’re taking prednisone, suddenly stopping the medication can cause the rash to reappear. This is called a rebound rash, and it can be more serious than the rash that cleared.

When a patient continues to have rashes

While medication can help clear the rash, a few people continue to develop new rashes. Having rashes most of the time can interfere with life. To help their patients feel more comfortable and lead fulfilling lives, dermatologists can prescribe long-term medication.

These medications help to calm your overactive immune system. Your dermatologist may prescribe methotrexate or another medication.

Another option may be a treatment called phototherapy. To get this treatment, you will need to go to your dermatologist’s office or a hospital a few times a week for several weeks. During this treatment, your dermatologist uses light to help clear your skin and calm down your immune system.

Some patients get relief by applying medication to their skin when they get a rash.

Your dermatologist will consider your individual needs and prescribe an appropriate treatment.

If you continue to have rashes after trying a treatment, tell your dermatologist. When one treatment fails, another may work.

When your dermatologist creates your treatment plan, it may include self-care to help you avoid new rashes. See what dermatologists recommend for their patients who have contact dermatitis at, Contact dermatitis: Self-care.

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References
Carol R. “Are you a rash whisperer?” Dermatol World. 2019:29(1):44-9.

Machler BC, Sung CT, et al. “To the editor: Dupilumab use in allergic contact dermatitis.” J Am Acad Dermatol. 2019;80(1):280-1.

Mowad CM, Anderson B, et al. “Allergic contact dermatitis: Patient diagnosis and evaluation.” J Am Acad Dermatol. 2016;74:1029-40.

Mowad CM, Anderson B, et al. “Allergic contact dermatitis: Patient management and education.” J Am Acad Dermatol. 2016;74:1043-54.

Tzortzi A, Kapetanstrataki M, et al. “Systematic literature review of e-cigarette-related illness and injury: Not just for the respirologist. Int J Environ Res Public Health. 2020 Mar 27;17(7):2248.

Usatine RP and Riojas M. “Diagnosis and management of contact dermatitis.” Am Fam Physician. 2010 Aug 1;82(3):249-55.

Written by:
Paula Ludmann, MS

Reviewed by:
Matthew Elias, MD, FAAD
Iltefat Hamzavi, MD, FAAD
Benjamin Stoff, MD, FAAD

Last updated: 12/14/20