Recently, we’ve all been introduced to the fact that chronic eczema often stems from an allergy to a mysterious chemical, metal, or molecule to which you or your child is coming in contact. In some studies, up to 70% of children who have chronic eczema have an allergy to one or more chemicals to which they are coming into contact with, in addition to having the genetic form of eczema (atopic dermatitis).
For example, I recently had a cute nine year old girl who came to my office with such severe eczema that her feet were about 80% covered in scabs and Band-Aids. She clearly had atopic dermatitis but also had a propensity for eczema on her hands and feet. When eczema is more severe and chronic on the hands and feet, a hunt for a culprit allergenic chemical should be initiated. In her case, we patch tested her and found her to be allergic to bacitracin; one of the antibiotics in the Neosporin that she and her mother had been smothering her scabs in several times a day with no improvement in the eczema. As you can imagine, once the Neosporin was withdrawn from her treatment plan, we were able to make some serious progress on the treatment of her eczema.
By finding what she was allergic to, this little girl’s life was transformed. She went from a child who said she would prefer the opportunity to wear shoes without pain over a trip to Disneyland, to a girl who could go to Disneyland wearing shoes; something we all take for granted.
Because chemical allergies are so common and yet difficult to determine in chronic eczema, it is always a good idea to seek out the help of a dermatologist who has experience in patch testing.
Patch testing is different from the standard prick testing that is done by allergists. With patch testing, the suspected chemical is tested on the skin for approximately 48 hours under occlusion followed by a series of patch test “readings” where the skin is observed for signs of allergic reaction in the exact spot where the suspected allergen was placed. Patch testing has been part of the physician’s armamentarium for deciphering the cause of eczema in adults for years. Unfortunately, the process has not been FDA approved for use on children in the US (though it was approved in Europe years ago) due to the insurmountable cost of approval (approximately $7 million dollars per chemical allergen).
With rates of allergy to nickel as high as 28.3% in children who were patch tested (Zug et al., 2008), and where the diagnosis of atopic dermatitis makes a child three times more likely to have an allergy to a chemical, don’t brush over the possibility of a chemical allergy in children regardless of their age. Don’t pass up the chance to change lives and bring shoe-wearing back into vogue! At the same time, when your teenager is dying for another piece of metal to be impaled through their skin, you can tell them a really good reason whey they shouldn’t do it! Don’t hold your breath that they will listen!