Allergies Health Center

Chemical Allergies

That moisturizer your friends swear by? Left your face red and scaly. The cleaner you've been using for years to make your bathroom sparkle? Made your hands itch and burn. For some people, the chemicals in shampoos, cosmetics, and detergents can trigger allergic skin reactions.

Causes of Chemical Allergies

Allergic skin reactions – what your doctor calls allergic contact dermatitis -- happen when your immune system overreacts to chemicals that are normally harmless. These chemicals can be in products that you are exposed to over and over, like cleaners, colognes, hair dyes, and personal care items.

Even if you've used these products before, you can still have a reaction.

Cosmetics and personal care products have a lot of potential allergens, things you could be allergic to:

• Fragrances in soaps, colognes, deodorants, body creams, cosmetics, detergents, and tissues
• Preservatives and antibacterials, added to many liquids to keep them from becoming rancid or contaminated
• Substances added to thicken, color, or lubricate a product
• Chemicals in permanent hair dyes and other hair products
• Formaldehyde resin, an ingredient in many nail care products
• Sunblocks or sunscreens, often found in cosmetic moisturizers, lip balms, and foundations

Symptoms of Chemical Allergies

Your skin is one of the first places where allergy symptoms can show up. They often appear 24 to 48 hours later, but can start as late as a week after exposure. Each person may have different chemical allergy symptoms. Some of the most common are:

• Red skin
• Scaly patches
• Blisters that ooze
• Burning or itching, which may be intense
• Swelling of the eyes, face, and genital area
• Hives
• Sun sensitivity
• Darkened, "leathery," and cracked skin

The worst of the reaction tends to be where you touched the thing you're allergic to. If you get the allergen on your finger and then touch another part of your body, like your face or neck, you can set off an allergic reaction there.

Because the symptoms of allergic contact dermatitis can be similar to other conditions, you should see a doctor if you have any of these symptoms.

Diagnosing Chemical Allergies

Often your doctor may be able to diagnose your allergy by doing a physical exam and asking you about your symptoms.

Sometimes your doctor may suggest you see an allergist for a skin test. The allergist places small samples of chemicals on your back and checks to see if you develop a rash.

Keeping track of your symptoms helps your doctor make a diagnosis. You should include details such as:

• What you were doing in the 24 to 48 hours before your outbreak
• Any products you were using before the outbreak
• How much of the product you were using and how often
• Where the product touched your skin (even places with no symptoms)
• Symptoms you have or had
• Any previous skin reactions