Contact Dermatitis

What is contact dermatitis?

Contact dermatitis is a physiological reaction that occurs after skin comes in contact with certain substances.

The majority of these reactions are caused by irritants to the skin, causing approximately 80 percent of cases. The remaining cases are caused by allergens, which trigger an allergic response. In allergic reactions, the reaction may not start until several days after exposure. Contact dermatitis, caused by an irritant that is not an allergic response, occurs from direct contact with the irritant.

Adults are most commonly affected by allergic contact dermatitis, but it can affect persons of all ages.

What causes contact dermatitis?

Some of the most common causes of contact dermatitis in adults and children include the following:

  • Soaps

  • Drool

  • Different foods

  • Detergents

  • Harsh baby lotions

  • Perfumes

  • Rubber (latex)

  • Antibiotics

  • Fragrances

  • Preservatives

Plants, as well as metals, cosmetics, and medications may also cause a contact dermatitis reaction:

  • Poison ivy. Poison ivy, which is part of a plant family that includes poison oak and sumac, is the most common cause of a contact dermatitis reaction.

  • Metals. Nearly 3,000 chemical agents are capable of causing allergic contact dermatitis. Nickel, chrome, and mercury are the most common metals that cause contact dermatitis:

    • Nickel is found in costume jewelry, belt buckles, and wristwatches, as well as zippers, snaps, and hooks on clothing.

    • Contact with objects that are chrome-plated, which contain nickel, will probably cause skin reactions in people sensitive to nickel.

    • Mercury, which is found in contact lens solutions, can cause problems for some sensitive individuals.

  • Cosmetics. Many types of cosmetics can cause allergic contact dermatitis. Permanent hair dyes that contain paraphenylenediamine are the most frequent causes. Other products that may cause problems include dyes used in clothing, perfumes, eye shadow, nail polish, lipstick, and some sunscreens.

  • Medications. Neomycin, which is found in antibiotic creams, is the most common cause of medication contact dermatitis. Penicillin, sulfa medications, and local anesthetics, such as novocaine or paraben, are other possible causes.

What are the symptoms of contact dermatitis?

The following are the most common symptoms of contact dermatitis. However, each individual may experience symptoms differently. Symptoms may include:

  • Mild redness and swelling of the skin

  • Blistering of the skin

  • Itching

  • Scaling and temporary thickening of skin

The most severe reaction is at the contact site. The symptoms of contact dermatitis may resemble other skin conditions. Always consult your doctor for a diagnosis.

Treatment for contact dermatitis

Specific treatment for contact dermatitis will be determined by your doctor based on:

  • Your age, overall health, and medical history

  • Extent of the reaction

  • Your tolerance for specific medications, procedures, or therapies

  • Expectations for the course of the reaction

  • Your opinion or preference

The best treatment is to identify and avoid the substances that may have caused the allergic reaction. The following are common treatment recommendations for mild to moderate reactions:

  • Thoroughly wash skin with soap and water as soon after the exposure as possible.

  • Wash clothing and all objects that touched plant resins (poison ivy/oak) to prevent re-exposure.

  • Use wet, cold compresses to soothe and relieve inflammation if blisters are broken.

  • Use barrier creams to block certain substances if there is a chance of re-exposure in the future. 

  • Topical and oral drugs may be recommended by your doctor to relieve itching. 

  • For severe reactions, always contact your doctor.

If the reaction is significant and the substance that caused it cannot be determined, your doctor may conduct a series of patch tests to help identify the irritant.