You go to the doctor with a mystery rash and he or she tells you that it is allergic contact dermatitis. Those few large words mean your skin has reacted to what it identifies as a foreign substance. The miserable, itchy rash that appears is your body's way of defending against whatever irritant you have come in contact with.

If this happens to you, you are not alone. Seven percent of all allergy sufferers struggle with skin allergies. Some of the common causes of allergic contact dermatitis:

• Perfumes and fragrances
• Cosmetics
• Soaps and detergents
• Rubber boots or shoes made with synthetic materials
• Jewelry and/or contact with metals such as nickel
• Poison ivy, oak and sumac plants

Note that all three plants - poison ivy, oak and sumac - produce an oily resin called urushiol (pronounced oo-roo-she-all). You can't see urushiol, but a very small amount can cause a very serious allergic reaction in highly sensitive people. Other plants, such as mangos, cashews and the poodle-dog bush (found in California) can also cause contact dermatitis.

What should you do if you have contact dermatitis?

Anytime you have a rash that appears and you are not sure of the cause, you should always consult a medical professional. A pharmacist or physician may be able to tell you what it is by looking at the rash and asking a few basic questions. Many doctors will recommend using an over-the-counter anti-itch treatment, as the first step. They may recommend prescription medications if the over-the-counter solutions do not work.

Be sure to call your doctor if you use a medication and the symptoms get worse, or if it becomes inflamed, hot or swollen as that may be a sign of infection.