Patch (Allergy) Testing
"Eczema" may develop for many reasons, ranging from a genetic
predisposition ("atopic dermatitis") to dry skin ("asteatotic
dermatitis"). Among the causes of eczema is "allergic contact
dermatitis (ACD)." ACD occurs when a person develops a rash after
a chemical touches their skin. Poison ivy is a typical example.
However, there are many potential allergens and ways they can
affect the skin.
If ACD is suspected, the appropriate next step is often "patch
testing". This involves placing sticky, allergen-containing patches on
the patient's back. If a dermatitis is found when the patches are
removed, an allergy is documented. The patient is provided with
information about that allergen as well as a list of products that do
not contain the allergen.
Our practice uses a panel of allergens recommended by the
American Contact Dermatitis Society as the most likely allergens in
North America. Additionally, the utility of this testing may be
increased if patients are tested with samples of their own cosmetics,
sunscreens, perfumes, topical medications and other products.