An overview of this common skin irritation, and how to control it.
Itchy skin, raised blisters, redness and swelling — if you’ve ever had contact dermatitis, you know it’s no fun. But what exactly causes the condition?
“Contact dermatitis is a reaction that can happen after your skin comes in contact with certain chemical substances,” said Basil Kahwash, M.D., an immunologist with Vanderbilt Asthma, Sinus and Allergy Program. “These substances can be irritants, which cause direct skin irritation and inflammation, or allergens, which trigger an allergic reaction.”
Symptoms of contact dermatitis
If an irritant is at fault, symptoms will show up quickly. If an allergen is the cause, however, it can take 24 to 48 hours for symptoms to emerge. Either way, contact dermatitis symptoms typically include:
- Mild redness and swelling of the skin
- Blistering of the skin
- Itching or burning of the skin
- Scaly, thickened skin
“These symptoms can mimic other skin conditions,” Kahwash said. “That’s why it’s important to seek the help of a provider who can help determine the cause of the rash.”
- Harsh baby lotions
- Perfumes and fragrances
- Certain foods
- Rubber (latex)
“It’s important to note that any of these irritants might also provoke allergic reactions,” Kahwash explained, “in addition to having irritant properties.”
- Poison ivy. Poison ivy is part of a plant family that includes poison oak and sumac. It’s one of the most common causes of a contact dermatitis reaction.
- Metals. Many 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. These will likely cause skin reactions in people sensitive to nickel.
- Mercury, which is found in contact lens solutions. This can cause a reaction in some people.
- Cosmetics. Many types of cosmetics can cause allergic contact dermatitis. Permanent hair dyes that contain paraphenylenediamine are often causes. Other products that may cause problems include perfumes, eye shadow, nail polish, lipstick and some sunscreens.
- Medicines. Neomycin is found in topical antibiotics, such as triple antibiotic ointment. It’s a common cause of medicine-related contact dermatitis. Penicillin, sulfa medicines and local anesthetics such as lidocaine are other possible causes.
Treatment for contact dermatitis
Diagnosing contact dermatitis is based largely on a health history and physical exam. Patch testing can be done to find the substance that’s causing the rash. A skin biopsy may also be taken.
Treatment will depend on your symptoms, age and general health. It will also depend on how severe the condition is. The best treatment is to find and stay away from the substances that may have caused the reaction. Here is some common treatment advice for mild to moderate reactions:
- Thoroughly wash the skin with soap and water as soon after the exposure as possible.
- Wash clothing and all objects that touched plant resins (such as poison ivy) 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.
“Your provider may also advise taking certain medications,” said Kahwash. “These include both oral and topical medications. Steroid creams or newer immunomodulator creams are used topically to control the irritation, while oral or injected steroids and oral antihistamines might be used in tandem to decrease inflammation and ease itching.”