Almost everyone gets this type of eczema at least once. We get contact dermatitis when something that our skin touches causes a rash. Some rashes happen immediately. Most take time to appear.
Allergic contact dermatitis
Some people have an allergic skin reaction.
You have had this type of contact dermatitis if you had a rash caused by:
Poison ivy
Nickel
Makeup you applied once or few times
Jewelry you wore for a long time without a reaction, such as a wedding ring
Jewelry you wore for only a few hours or days
Latex gloves
Irritant contact dermatitis
This type is more common. It develops when something irritates the skin. With enough contact, most things will irritate our skin.
A person diagnosed with any of the following has irritant contact dermatitis:
Diaper rash
Acid burn
Dry, cracked hands due to lots of contact with water
Irritated skin around the mouth due to lip-licking
When a toxic substance touches our skin, the skin is quickly irritated.
You’ve had irritant contact dermatitis if your skin reacted to a toxic substance like:
Battery acid
Bleach
Pepper spray
You can also develop irritant contact dermatitis when you have lots of contact with less irritating substances like:
Water
Foods
Soap
People often develop irritant contact dermatitis at work. Beauticians, nurses, bartenders, and others who spend lots of time with wet hands get this. It often starts with dry, cracked hands. In time, the skin on their hands may begin to sting and burn. The skin becomes very tender. Sometimes, the skin itches and bleeds.
When a rash does not clear within a few weeks, you should see a dermatologist. When contact dermatitis develops, treatment is important. It can prevent the contact dermatitis from worsening and help your skin heal.
Symptoms
When to seek immediate medical care
A few people develop a severe allergic reaction known as anaphylaxis (an-uh-fuh-lax-sis). Symptoms occur within seconds or minutes.
A person may have:
Difficulty breathing due to swelling in the throat
Swollen face and/or eyes
Confusion
In short, the entire body reacts. If you have any of these symptoms, you need immediate medical care.
Allergic contact dermatitis
This skin condition occurs when you have an allergic reaction to something that comes in contact with your skin.
Signs and symptoms rarely appear on contact. It may take a few hours for your skin to react. If this is your first time that your skin has an allergic reaction to that substance, weeks may pass before you notice anything.
When signs and symptoms appear, you may have:
Itchy skin (often intense)
Rash (skin red, swollen, and hot)
Excessively dry skin
Burning
Stinging
Hives (round welts on the skin that itch intensely)
Fluid-filled blisters
Oozing blisters that leave crusts and scales
If exposure to the allergen continues, your skin may:
Flake and crack
Become scaly
Darken, thicken, and feel leathery
Irritant contact dermatitis
Many substances can irritate our skin. Soap, shampoo, food, and water are mild irritants. With lots of exposure, these can cause irritant contact dermatitis. Getting a strong irritant like battery acid or fiberglass on your skin just once also can cause irritant contact dermatitis.
The signs and symptoms differ for mild and strong irritants.
With a mild irritant the signs and symptoms develop over time, and you’ll gradually notice:
Dry, chapped skin
With repeat exposure, patches of itchy, red, swollen, and scaly skin develop. By this time, each time something that can irritate the skin touches the affected skin, you may feel stinging and burning right away.
If exposure continues, the skin may crack, get scaly, and become excessive dry.
Sores and blisters may develop and erupt, causing crusts and scales.
On contact or within a few hours, strong irritants can:
Burn, sting, and/or itch
Become inflamed (red and swollen)
Develop fluid-filled blisters
When you have irritant contact dermatitis, many things can irritate your skin. You may feel pain on contact. With repeat exposure, the condition worsens.
Reduced quality of life
This skin condition often affects a person’s quality of life. The rash can make many daily activities painful, especially when the rash forms on the hands. The rash can cause:
Missed workdays
Inability to enjoy leisure activities
Loss of sleep
Causes and Risk Factors
Who gets contact dermatitis?
Anyone can develop contact dermatitis. People working in certain professions have a higher risk. In fact, this is so common that your doctor may tell you that you have occupational dermatitis.
People who are more likely to get occupational dermatitis include:
Nurses (and other health care workers)
Beauticians
Bartenders
Chefs (and others who work with food)
Florists (and others who work with plants)
Construction workers
Janitors’
Mechanics
Plumbers
Nurses and beauticians often develop dry, cracked skin on their palms and fingers. Wearing latex gloves frequently throughout the day causes some people to develop an allergy to latex. A common sign of this allergy is itchy, inflamed hands.
You also have a greater risk of developing contact dermatitis if you have (or had) one of these medical conditions:
Asthma
Hay fever
Atopic dermatitis (often called eczema)
Your environment also plays a role. Extreme heat or cold, high humidity, and very dry air make the skin more vulnerable.
What causes contact dermatitis?
A person develops contact dermatitis when something that touches the skin does one of the following:
Irritates the skin
Causes an allergic reaction
When the skin is irritated, a person develops irritant contact dermatitis. Anyone can develop this type of contact dermatitis. It happens when something damages the outer layers of skin.
Almost any chemical, including water, can damage the skin with enough contact. Toxic substances like fiberglass and turpentine quickly damage the skin. Many people develop irritant contact dermatitis when they work with hair dyes, solvents, oils, paints, varnishes, foods, or metalworking fluids.
An allergic reaction causes allergic contact dermatitis. People develop allergic reactions to many substances.
Some of the most common causes of allergic contact dermatitis are:
Poison ivy
Nickel (used in cell phones, jewelry, eyeglass frames, zippers, belt buckles)
Nail cosmetics: Nail polish, adhesives
Fragrances
Latex
Cement
Many people touch a substance for years before an allergy develops.
Sometimes a trigger is needed for an allergic reaction to occur. Allergic contact dermatitis may only occur when the skin:
Sweats
Has ultraviolet rays (sun, tanning bed) hit it
More than 3,600 substances can cause allergic contact dermatitis. These substances include preservatives in cosmetics, antibiotics applied to the skin, animal dander, dyes in clothing and shoes, and rubber.
With thousands of causes, successfully treating this skin condition can take a bit of detective work. Dermatologists frequently treat this condition. In fact, this is one of the most common reasons to see a dermatologist.
Diagnosis and Treatment
How dermatologists diagnose contact dermatitis
To diagnose this common skin condition, dermatologists:
Examine your skin, paying close attention to the rash.
Ask about current and past health issues.
Ask questions to help them determine what is causing the rash.
Finding the cause can require a bit of detective work. Your dermatologist may ask you questions about your work, free time, pets, and skincare products. Be sure to tell your dermatologist about all the cosmetics you use. If you or a close family member uses a skin lightener, be sure to mention this, too.
If your dermatologist suspects that you have an allergy, patch testing may be recommended. This offers patients a safe and effective way to find out if your skin has developed an allergic reaction to anything.
What happens during patch testing?
If patch testing is recommended, the following will happen:
Patches containing small amounts of substances to which you may be allergic will be applied to your skin, usually on your back.
You keep the substances on your skin for a specific amount of time, usually 2 days.
You return to your doctor’s office so that the doctor can check your skin for reactions.
You may need to keep some patches on your skin for a longer time and see your doctor again in a few days.
To find out if the allergen is causing your rash, you will need to avoid that substance. For example, if the test shows that you have a nickel allergy, you may need to:
Stop wearing jewelry and clothing (zippers, fasteners) that contain nickel.
Cover your cell phone with a case to avoid touching the metal.
Get a pair of eyeglasses made without nickel.
If your skin clears when you avoid the allergen, it is likely the cause of your rash.
How dermatologist treat contact dermatitis
Treatment is the same for both types of contact dermatitis. Avoid what is causing your rash. If avoiding the cause will be difficult, ask your dermatologist for help. For example, if you are allergic to latex but must wear exam gloves, your dermatologist can recommend another type of glove that you can wear. If you must work outdoors where poison ivy grows, your dermatologist can recommend a protective barrier cream and clothing that can help.
Once you can avoid the cause, your rash should clear.
To relieve your symptoms, a dermatologist may recommend the following:
Mild reaction: Antihistamine pills, moisturizers, and a corticosteroid that you can apply to your skin. Most patients apply the medicine twice a day for 1 week and once a day for 1 to 2 weeks.
Oatmeal baths can relieve discomfort.
Severe reaction: If you have a lot of swelling, your face swells, or the rash covers much of your body, you may need a strong medication. Your dermatologist may prescribe prednisone. It is important to take this medication exactly as directed to avoid another flare. Wet dressings can help soothe skin that has lots of oozing and crusting. If your dermatologist recommends wet dressings, you’ll receive instructions to help you make these at home.
If you have an infection, your dermatologist may prescribe an antibiotic. Some patients need light therapy to calm their immune systems. Your dermatologist may refer to this as phototherapy. If you avoid what caused the rash, your skin will clear. Most people see clear skin within 1 to 3 weeks. Clearing may take longer if poison ivy, poison oak, or poison sumac caused your rash. The first time you have an allergic reaction to one of these plants, the rash may linger for 6 weeks. If you get another rash, your skin should clear within 10 to 21 days. Once your skin clears, you must continue to avoid what caused your rash. If your rash does not clear, you should tell your dermatologist. You may need extra help.
Systemic contact dermatitis
Some people develop a rash even when they avoid touching the allergen. A rash can appear when the substance to which you have an allergy gets inside your body. The medical term for this condition is systemic contact dermatitis.
The allergen can get inside your body in different ways. You could:
Eat food that contains the allergen
Inhale or inject a medicine that contains the allergen
Use birth control (IUD or spermicide) that contains the allergen
While rare, some people develop a rash because the fillings in their mouth contain mercury. They could only get rid of the rash when a dentist replaced their fillings with fillings that did not contain mercury. Trying to find everything that contains the allergen can be a challenge. Your dermatologist may be able to help you create a list of things you need to avoid. The list often varies from region to region.
The outcome for patients with contact dermatitis
By avoiding what caused the rash, most people can avoid flare-ups. If you work with substances that caused the rash, you can still avoid a rash. Your dermatologist can recommend ways to work and products to use. More than 80% of people diagnosed with occupational dermatitis successfully manage the condition and recover without any problems.
References
American Academy of Dermatology:
“Contact dermatitis.” Medical Student Core Curriculum. Last update July 2011.
“Musicians at risk for common skin condition.” News release issued March 16, 2012.
“Saving face: Dermatologists helping patients identify source of facial allergic contact dermatitis.” News release issued August 1, 2013.
Ehrlich A. “Fragrance Allergy.” Presented as a focus session at: The American Academy of Dermatology’s ACADEMY ’06 Summer Meeting. July 2006; San Diego.
Saary J, Qureshi R. “A systematic review of contact dermatitis treatment and prevention.” J Am Acad Dermatol. 2005;53:845-55.
