Allergic Contact Dermatitis - Contact Dermatitis

Overview, Causes, & Risk Factors

Contact dermatitis is a bumpy patch of red, itchy, flaky skin. It occurs when someone has an allergic reaction after coming into contact with something that irritates his or her skin. The substance that irritates the skin is known as an allergen, and it triggers the allergic reaction.

What is going on in the body?

Contact dermatitis occurs when someone has been exposed to a substance that irritates the skin or causes an allergic reaction. People are more likely to have contact dermatitis if they have sensitive skin or a pre-existing skin condition.

What are the causes and risks of the condition?

Some of the more common allergens that trigger contact dermatitis include the following:

soaps

fabric softeners

perfumes

cosmetics

nickel, which may be found in jewelry, zippers, buckles, hair ornaments, and other accessories

deodorants

plants, such as poison ivy, poison oak, or poison sumac

rubber, such as in shoe linings or latex gloves

hair dyes, especially permanent dyes containing paraphenylenediamine, or PPD

dyes used in clothing, which may contain PPD

certain local anesthesia medications, including benzocaine, which is chemically related to PPD

neomycin, an antibiotic commonly found in over-the-counter antibiotic ointments

chromates, which are chemicals commonly found in cement, leather, paints, matches, and anti-rust products

Symptoms & Signs

What are the signs and symptoms of the condition?

The allergic reaction of contact dermatitis causes skin to redden, itch, and form blisters. The skin may crack, and a sticky fluid may ooze out. Finally, the skin may become dry and peeling may occur.

Diagnosis & Tests

How is the condition diagnosed?

Contact dermatitis is usually self-diagnosed. Repeated rashes are typical. This can, however, become a regular event. The person's healthcare provider may suggest doing a patch test. This test applies different substances to the skin so the reaction can be observed.

Prevention & Expectations

What can be done to prevent the condition?

To prevent contact dermatitis, a person can take the following steps:

Substitute vinyl gloves, if he or she has an allergic reaction to latex or other forms of rubber.

Choose hypoallergenic perfumes, cosmetics, deodorants, and jewelry.

Wear gloves, long pants, and long sleeves for protection from poison ivy, poison oak, and poison sumac plants.

Apply hypoallergenic lotion to skin often.

Once an individual is aware of allergens that trigger their contact dermatitis, they should take steps to avoid the trigger. For example, people sensitive to PPD can use temporary hair rinses or dyes that are PPD-free. A person sensitive to neomycin ointment should use antibiotic ointments that don't contain that medication.

What are the long-term effects of the condition?

If contact dermatitis is not treated effectively, the individual may have almost constant outbreaks of the allergic reaction. Skin may become very irritated, with skin thickening and changes in color. Secondary infections can occur.

What are the risks to others?

Contact dermatitis is not contagious and poses no risk to others.

Treatment & Monitoring

What are the treatments for the condition?

Treatment of contact dermatitis may include the following measures:

Avoiding and removing allergens.

Applying Burow's solution or cool water compresses.

Taking oral antihistamines to relieve itching.

Using antibiotics as needed for infection.

Applying over-the-counter or prescription corticosteroid creams, such as hydrocortisone or betamethasone.

Taking oral steroids such as prednisone.

Avoiding hot water, which worsens the allergic reaction.

Avoiding scratching the infected area to prevent its spread.

Applying hypoallergenic lotion to the skin often.

What are the side effects of the treatments?

Corticosteroid creams may cause thinning of the skin over time. Oral corticosteroids can decrease the body's ability to fight infection. Antihistamines may cause drowsiness, dry mouth, and dizziness. Antibiotics may cause rash, stomach upset, or allergic reactions.

What happens after treatment for the condition?

After the contact dermatitis is gone, it's important to avoid future contact with the substance that caused the allergic reaction.

How is the condition monitored?

Any new or worsening symptoms should be reported to the healthcare provider.