Q: I have been trying to find out the difference between atopic dermatitis and contact dermatitis. I have noticed a rash, severe at times while wearing certain clothing. It is usually around my feet and ankles. The rash goes away after removing the clothing and boots and never occurs in my normal clothing. Any information you may have will be beneficial.

A: Apples and oranges.

Atopic dermatitis is a pruritic dermatitis that occurs more commonly in individuals with either a personal or family history of "hay fever", asthma or eczema. This is associated with the presence of the "allergic" antibody which is IgE.

Allergic contact dermatitis has nothing to do with the "allergic antibody" but it is an immune mediated skin rash at the site of contact with a chemical allergen. An example of this type of rash would be the rash with poison ivy or the skin reaction to the nickel metal in costume jewelry in an "allergic" individual. This is medicated by sensitized T-cells and not IgE.

I hope this helps. Just as apples and oranges are both fruits, atopic dermatitis and allergic contact dermatitis both affect the skin.