Eczema types: Contact dermatitis causes

What causes contact dermatitis?

There are two main types of contact dermatitis. The rash and other symptoms of contact dermatitis develop when something either:

• Irritates your skin, causing irritant contact dermatitis

• Triggers an allergic reaction, causing allergic contact dermatitis

Irritant contact dermatitis: When something injures and then irritates your skin, it causes this type of contact dermatitis. Common irritants that can injure your skin, causing irritant contact dermatitis, include:

• Detergents and bleach

• Plants

• Fruit juice

• Hand sanitizers

• Soaps

• Gasoline and diesel oil

• Disinfectants

• Fertilizers and pesticides

• Chemicals used to remove grease, oils, and cutting fluids

The above list gives you an idea of what can irritate your skin. It’s important to know that these are just a few of the many things that can irritate your skin. Under the right circumstances, even water can cause irritant contact dermatitis.

For example, if you dip your hands in water throughout the day and do this nearly every day, the water can strip away your skin’s protective barrier. Without a protective barrier, you have injured skin. If you continue to injure your skin by dipping your hands in water frequently, you develop irritant contact dermatitis.

Frequent handwashing can also cause irritant contact dermatitis. To reduce your risk, use mild soaps and cleansers. Applying a fragrance-free hand cream after each hand washing also helps.

Skin care products are a common cause of contact dermatitis

Even “natural” or “clean” skin care products can cause a skin reaction.

Allergic contact dermatitis: If what touches your skin causes an allergic reaction, you develop this type of contact dermatitis.

It can be difficult to figure out what’s causing allergic contact dermatitis because it takes time for the rash to appear. When your skin touches an allergen (what you’re allergic to), this triggers your immune system. A series of events occur inside your body before your skin reacts. For this reason, it can take hours or days before you develop a rash and symptoms.

To complicate matters, “there are more than 15,000 allergens,” says dermatologist Bruce Brod, MD, FAAD, who has a special interest in contact dermatitis.

While there are more than 15,000 allergens, some are more common. The most common causes of allergic contact dermatitis are:

Some people only develop contact dermatitis after certain chemicals touch their skin and then ultraviolet (UV) light, such as sunlight, hits their skin. The rash only appears where the UV light hits their skin. Dermatologists refer to this type of allergic contact dermatitis as photocontact dermatitis.

Some people have a higher risk of developing contact dermatitis

While it’s possible for anyone to develop contact dermatitis, some people have a greater risk.

If you have a skin condition that lessens your skin’s ability to protect you from germs and other invaders, you have a greater risk. Conditions that cause this include atopic dermatitis (AD), stasis dermatitis, and leg ulcers. When your skin is less able to protect you, it’s easier for something to irritate your skin or trigger an allergic reaction.

People who work in certain jobs also have a higher risk. Anyone who dips their hands in water throughout the day or works with harsh chemicals has a higher risk.

As for specific jobs, studies show that people who work in one the following industries or jobs have a higher risk of developing contact dermatitis:

• Health care workers

• Food service workers, chefs, and bartenders

• Construction workers

• Cosmetologists (including hairstylists, nail technicians, makeup artists)

• Florists

• Machinists

• Mechanics

• Agricultural workers

• Natural resources and mining

• Manufacturing

In the United States, contact dermatitis is one of the most common diseases caused by the workplace.

What can get rid of contact dermatitis?

If you can figure out what’s irritating your skin or causing an allergic reaction, you can get rid of the contact dermatitis. To heal your skin, you need to avoid what’s causing your skin to react.

For example, if you smoke e-cigarettes and have a rash on your lips and the hand that you hold the e-cigarette with, the cause is probably e-cigarettes. If you stop using e-cigarettes and the rash clears on its own, you’ve likely found the cause.

Finding the cause isn’t always easy. If you continue to have a rash, see a board-certified dermatologist. This doctor can tell you whether you have contact dermatitis, an infection, or another skin condition.

A dermatologist can also help when you cannot avoid what’s causing your contact dermatitis. For example, if you work with harsh chemicals or need to wash your hands frequently throughout your workday, a dermatologist may recommend a glove that can protect your skin or a skin care product that helps.

Find out what you can expect when you see a dermatologist at, Contact dermatitis: Diagnosis and treatment.

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References
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.

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

Wilkinson SM, “Occupational dermatoses.” In: Bolognia JL, et al. Dermatology. (fourth edition). Mosby Elsevier, China, 2018: 274-85.

Written by:
Paula Ludmann, MS

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

Last updated: 12/14/20