Allergic Rashes and Everyday Products
Allergic rashes are often caused by the products we use on a daily basis. When a medical professional identifies a chemical allergy we call it to contact dermatitis because contact with the chemical often causes an allergic reaction in the form of a skin rash.
The list of contact allergens a person can get from having contact with substances range in the thousands since so many of today’s products are filled with preservatives and oils. However, only about two dozen of these are the main contact allergens that affect patients. As an allergy specialist, I can easily test these specific allergens using a special tape (no needles necessary!) to determine if a contact allergen is the cause of a person”s rash.
What Causes an Allergic Skin Rash?
Trying to unravel the cause of contact dermatitis can be compared to being the equivalent of Sherlock Holmes unraveling a mysterious murder. Often, the best allergy treatment is knowledge–scientific evidence and a good understanding of the patient”s history–to know why their skin had an allergic reaction.
I had a patient several years ago who had a recurrent rash along his scalp and neck. It was red and very itchy, so he came to me for help. To try to determine the problem, I used the contact dermatitis patch testing (the special tape) and his results showed he was allergic top-phenylenediamine.
P-phenylenediamine is a common chemical used in hair dye, so I asked him curiously if he dyed his hair? He looked at me with a smile and asked: “does it look like I dye my hair?” Silly question on my part. His hair was completely gray.
He went on to say he couldn’t dye his hair because when he did, he always got intense itching and rashes on his scalp. I thought about the situation carefully and asked: ” Does your wife dye her hair?” He said: ” Of course, she wouldn’t think of being gray!”
My A-HA moment came when I told him I thought he was getting exposure to his wife”s hair dye from her pillow!
Contact allergens can seep into clothing or linens very easily–items that often come in contact with our skin. If he shared or switched pillows with his wife he would be getting this allergen on his scalp. We treated his rash with some cream, and he later informed me that he and his wife could co-exist harmoniously–avoiding an allergic reaction–as long as they kept their pillows separate!
Perfumes are also notorious offenders for causing contact allergy. A common ingredient in too many perfumes and colognes, as well as shampoos, is Balsam of Peru. This chemical gives products a nice small and is cheap enough to be widespread in its use.
I have seen many patients’ in my time who have allergic rashes, that were caused by this allergen. The irony in many cases is that people don”t suspect this allergy because they use the product in one area and the rash appears somewhere else.
The reason for this is that the skin on our fingers and palms (the area that initially touches these chemicals) is thicker and less likely to trigger an allergic reaction than the skin elsewhere on our body. We touch our face, eyelids and neck a lot more than we actually realize and, as the skin is much thinner in these areas, this is where the rash often appears.
A classic example of a rash spread like this is a nail polish allergy. I see many women who develop a rash on their face, neck or around their eyes due to a chemical found in many nail polishes –toluene sulfonamide. As you would expect, many of my female patients are not too happy when they find out they can no longer use many of their favorite types of nail polish.
The Good News…
Luckily, contact allergens are treatable with simple cortisone creams and, of course, future avoidance. The testing for these allergies is painless and easy, so if you are suffering from allergic rashes get in touch! Technology can also play a part in helping you avoid allergies. There are lots of Apps available that tell you where certain chemicals are in products and how you can find alternatives.
I”m sure if Sherlock Holmes returned to medicine from crime sleuthing he would love diagnosing Allergic rashes!
Dr. Dean Mitchell
Mitchell Medical Group, NYC & Long Island