What is the difference between atopic dermatitis and contact dermatitis?
Atopic dermatitis appears early in life as chapped skin in areas that go through frequent wet-dry cycles (for example, the area around the mouth in babies) or in skin folds. Atopic dermatitis patients are susceptible to skin infections, which often make inﬂammation worse. Protein molecules, such as foods, or pollen or latex can penetrate broken and in-ﬂamed skin, and atopic patients are especially likely to develop an immune response to these types of allergens.
Irritant contact dermatitis can occur even in patients without a genetic predisposition to atopic dermatitis under extreme conditions. Examples of such conditions would be frequent wet work with harsh chemicals, such as the work done by machine operators or hairdressers.
In any circumstance where skin is inﬂamed and broken, allergic contact dermatitis can develop to allergens in contact with the skin, such as components of topical medications, rubber in gloves, and preservatives or fragrances in personal care products.
What are allergens, and what are the most common allergens that aggravate eczema?
Allergens are any molecule in the environment that can penetrate skin and cause an inﬂammatory response. Most allergens cause a rash in only a small number of people, but some, like poison ivy, cause a rash in most people who have skin contact with it. Allergic contact dermatitis usually develops to small, non-protein molecules such as preservatives or metals. Atopic dermatitis patients can also develop contact dermatitis to plant proteins such as oat or dandelion.
What is the wet-dry cycle, and why is it bad for eczema?
The wet-dry cycle refers to the drying of skin dampened with water or perspiration. Imagine a muddy ﬁeld: if the sun dries the ﬁeld quickly, the mud cracks; if it dries slowly on a cloudy day the mud stays smooth. Skin with eczema is especially likely to crack in low humidity conditions when it dries quickly. Applying a moisturizer to slow the drying of wet skin is therefore especially important in the winter when the humidity is lower.
What is the best information I can provide my doctor when I have my appointment?
Describe environmental factors (season, skin care products, antibiotics, etc.) that make your eczema better or worse.
What is the Contact Allergen Replacement Database (CARD)? And can I gain access to it without having done a patch test?
CARD and CAMP (Contact Allergen Management Program) are databases that can suggest personal care products free of speciﬁed allergens.
It is impossible for patients or physicians to accurately diagnosis allergic contact dermatitis to the speciﬁc components of items that touch the skin without patch testing. Therefore, access to these databases is restricted to patients who have undergone patch testing by a dermatologist.
I work in a restaurant and am required to wash my hands very frequently. My hands are cracked and dry; obviously I have hand eczema. What can you suggest I do at work to help the situation?
Use an alcohol-based hand sanitizer on your ﬁngertips to substitute for hand washing when-ever possible. Although the alcohol will sting on open areas, you will at least spare more of the skin from the wet-dry cycles that cause the cracking in the ﬁrst place.
Wear waterproof gloves for all wet work, but always wear cotton gloves underneath these waterproof gloves. The cotton gloves will absorb perspiration that would wet the skin and cause cracking when the gloves are removed and the hands dry rapidly.
What might be some surprising allergens that people are not aware of?
Medications applied to skin that is already inﬂamed are frequent causes of contact allergy. Examples include hydrocortisone, neomycin, bee glue, vitamin E, and lanolin.
Dr. Susan T. Nedorost is Director of the Dermatitis (atopic, allergic, and occupational) Program in the Department of Dermatology at University Hospitals Cleveland Medical Center. Dr. Nedorost is an international expert in the diagnosis, education, and treatment of occupational dermatitis, environmental dermatitis, hand dermatitis and persistent or unresponsive dermatitis utilizing patch testing as a diagnostic tool. She served on the National Eczema Scientific Advisory Board for several years.