What is contact dermatitis?
Contact dermatitis is a physiological reaction that occurs after
skin comes in contact with certain substances.
About 80 percent of these reactions are
irritant reactions and 20 percent are allergic reactions. In allergic
reactions, the reaction may not be immediate, but may start after several
Adults are affected by allergic contact
dermatitis more than young children or the elderly.
What does contact dermatitis look
The skin becomes red, itchy and inflamed, often with blisters.
The most severe reaction is at the contact site. Scratching the area will
spread the rash, in most cases.
What causes allergic contact
Plants, as well as metals, cosmetics, and medications may cause a
for Contact Dermatitis
the American Academy of Allergy, Asthma and Immunology:
substances that may cause allergic contact dermatitis is best. For
mild to moderate reactions, follow these precautions:
1. Thoroughly wash skin with
soap and water as soon after exposure as possible.
2. Wash clothing and all
objects that touched plant resins to prevent re-exposure.
3. Use wet, cold compresses
to soothe and relieve inflammation if blisters are broken.
4. Calamine lotion may
relieve itching. It also acts as a drying agent.
5. For severe reactions,
contact your physician.
- Poison ivy
Poison ivy, which is part of a plant family that includes poison oak
and sumac, is the most common cause.
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, cause problems for some sensitive
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, perfume, 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.