Understanding contact dermatitis and eczema

NetWellness August 31, 2011,  Contact dermatitis is an inflammation of the skin caused by contact with a certain substance. The substance, which can range from poison ivy to fragrance, prompts an allergic reaction of the skin. This skin inflammation can vary from redness to widespread rashes with open sores. Eczema (often used synonymously with the term dermatitis) can also result from an inherited dry, cracked skin with allergies to foods or pollen (atopic dermatitis) or from leg swelling (stasis dermatitis).

Understanding contact dermatitis Atopic dermatitis almost always starts during childhood, but contact dermatitis can first appear at any age. Patients are often diagnosed with atopic eczema during adulthood; however, this is most likely contact dermatitis. Contact dermatitis is curable, which is good news for many undiagnosed patients who continue to use potentially harmful steroids, in both cream and pill form, to treat their "eczema." Contact dermatitis is triggered by substances that cause an allergic reaction in certain people. Examples include:

‧Poison ivy, poison oak and poison sumac. ‧Preservatives in personal care products (in industrial environments, preservatives are referred to as biocides). ‧Fragrances. ‧Adhesives. ‧Chemicals used in the workplace. ‧Dyes and finishes in fabrics/clothing.

Allergens cause a contact allergy when they touch the skin, and this reaction is almost always delayed. Immediate reactions can occur such as to latex, but skin takes several days after contact before a rash develops in response to most allergens. Respiratory allergies, in contrast, are much more immediate. For example, a person with a common allergy to pollen who is running through a grassy field would notice their nose running within minutes. On the other hand, if that person in the field had an allergy to the poison ivy, the rash may not be visible for three to seven days. In fact, this single brief contact with poison ivy can cause a rash that lasts for a month. This makes it difficult for patients to diagnose the source of their contact dermatitis or eczema. It's understandable to presume that a persistent rash, such as one that lasts for a month, is caused by something you come in contact with frequently. However, given the delayed reaction associated with contact dermatitis, the source could have been a substance that briefly or infrequently touched the skin. A contact dermatitis specialist has the tools to accurately determine the particular allergen.

Breakthrough testing, breakthrough results  Patch testing is the gold standard for diagnosing a contact allergy. In this test, a dermatologist applies patches that each contains a specific type of allergen. The patient wears the patches for 48 hours and returns to the office near day three and day seven of the test. This is because the reaction taking place between the skin and allergen is delayed, meaning it will take the skin time to show visible signs of an allergy. When the dermatologist notices redness at the test site, they have identified a substance to which the person is allergic. Physicians belonging to the American Contact Dermatitis Society even have access to unique software that allows the information gathered in the patch test to be translated into a tool for daily life. The software determines what substances the patient should avoid based on his or her allergy and what substances would make good alternatives. Even more useful, the substances to avoid and the substances to use are listed by category and brand name. In addition to useful software, contact dermatitis specialists use a patch test process that tests 75 to 100 allergens in most people. They can also add tests for other allergens based on the occupation of the patient. By avoiding the allergen causing the contact dermatitis, the patient can actually be cured of the condition.

The danger of steroids and contact dermatitis Often, contact dermatitis is diagnosed in patients as atopic eczema. In order to treat the symptoms, some doctors may prescribe corticosteroid skin creams or steroid pills (for example, Prednisone) for the patient. But this does not provide a cure and may present dangerous side effects for the person such as: glaucoma and cataracts when corticosteroid ointments or creams are used near the eyes for extended periods of time; thinning skin; weight gain; bones that break more easily; worsening of contact dermatitis or eczema. The best way to ensure you are getting the latest and safest treatment for your eczema or contact dermatitis is to see a contact dermatitis specialist. Information on finding a specialist near you can be found through the American Contact Dermatitis Society.