What is contact dermatitis?
Contact dermatitis is a reaction that occurs after your skin comes in contact with certain substances.
Skin irritants cause most contact dermatitis reactions. Other cases are caused by allergens, which trigger an allergic response. 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.
Allergic contact dermatitis most commonly affects adults, but it can affect people of all ages.
What causes contact dermatitis?
Some of the most common causes of contact dermatitis include:
- Different foods
- Harsh baby lotions
- Rubber (latex)
Plants, metals, cosmetics, and medications may also cause a contact dermatitis reaction:
Poison ivy is part of a plant family that includes poison oak and sumac. It is the most common cause of a contact dermatitis reaction.
Nearly 3,000 chemical agents can cause allergic contact dermatitis. Nickel, chrome, and mercury are the most common metals that cause contact dermatitis:
- Nickel is found in costume jewelry, and belt buckles. Watches, zippers, snaps, and hooks on clothing may also contain nickel.
- Chrome-plated items, which contain nickel, will probably cause skin reactions in people sensitive to nickel.
- Mercury, which is found in contact lens solutions, can cause a reaction in some people.
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.
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 person may experience symptoms differently. Symptoms may include:
- Mild redness and swelling of the skin
- Blistering of the skin
- Scaly, thickened skin
The most severe reaction is at the contact site. The symptoms of contact dermatitis may look like other skin conditions. Always consult your health care provider for a diagnosis.
How is contact dermatitis diagnosed?
Diagnosis is usually based on a medical history and physical exam.
How is contact dermatitis treated?
Specific treatment for contact dermatitis will be determined by your health care provider 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 inflammation if blisters are broken.
- Use barrier creams to block certain substances if there is a chance of re-exposure in the future.
- Medications you put on your skin or ones you take by mouth may be recommended by your health care provider to relieve itching.
- Avoid scratching the rash to prevent a bacterial infection.
- For severe reactions, always contact your health care provider.
If the reaction is significant and the substance that caused it can't be determined, your health care provider may do a series of patch tests to help identify the irritant.
Can contact dermatitis be prevented?
The only way to prevent contact dermatitis is to avoid contact with the irritant or allergen that causes it.
Key points about contact dermatitis
- Contact dermatitis is a physiological reaction that occurs after skin comes in contact with certain substances.
- Skin irritants cause most contact dermatitis reactions.
- Allergens can cause an allergic reaction that results in contact dermatitis.
- It is important to identify the cause of your contact dermatitis so you can avoid contact with that substance.
- Topical and oral drugs may be recommended by your health care provider to relieve itching.
Tips to help you get the most from a visit to your health care provider:
- Before your visit, write down questions you want answered.
- Bring someone with you to help you ask questions and remember what your provider tells you.
- At the visit, write down the names of new medicines, treatments, or tests, and any new instructions your provider gives you.
- If you have a follow-up appointment, write down the date, time, and purpose for that visit.
- Know how you can contact your provider if you have questions.