Thread: contact dermatitis

One of these days when I retire, I plan to write a book on practical skin care. Towards that end, I am slowly starting to write stuff which I hope may develop further into chapters later on. With this in mind, I'm posting info that might be of use for folks in this forum. If any of you find it helpful, or can think of other areas related to the skin that would be helpful, let me know.

For starters, I want to talk about contact dermatitis, which I deal with quite a bit in my work. With all of the skin products people use around here on their skin, I think its a good subject for our group.

Contact dermatitis is more common than people appreciate, and lots of topical products can produce skin reactions. For example, neosporin causes a contact allergy in about 1% of all people (thats why dermatologists, despite neosporin's advertising claims, rarely recommend this product). The second most common type of contact allergy is to certain metals, especially nickel. For that reason, if you see a small itchy circular rash just below the belly button, its usually due to a nickel trouser snap or belt buckle.

Because us shavers use a variety of things on our skin, preshave, shave or post shave, products, colognes, sunscreen moisturizers etc., if you do develop a rash on the skin, sometimes its hard to know which product you are putting on your skin might be causing it, or is it just razor burn. This is when a bit of knowledge about contact dermatitis comes in handy.

Contact dermatitis is a delayed hypersensitivity reaction. What this means is that if you put something you are allergic to on the skin, it will take 1-2 days for you to actually see the rash. Poison ivy or poison oak are good examples. You usually see the rash only a day or two after you went hiking or were clearing brush, not immediately afterwards.

Because of this delayed timing, many people do not immediately connect the application of the skin product with the onset of a facial rash. Its also good to keep in mind that people can become sensitized or develop an allergy over time. That means that something that might have worked just fine on your skin, could eventually start to cause a rash.

If you are getting a rash on your skin and want to determine whether a particular topical product might be producing a contact dermatitis, an easy way to test this is to do what is called a use test. You simply rub a small amount of the substance in question on a small area of your inner forearm, once a day. Keep applying small amounts to the very same area on the forearm once a day for a week. Don't apply anything else to that area. If you have a reaction to that substance, you should see redness and itching sometimes a couple small blisters.

If thru this test you do have an allergy to a particular product, then its a good idea to go to the dermatologist and get a patch test. In that way, you can find out what ingredient in the particular skin product you are allergic to. That way, anytime you consider a new product for the skin, you can look at the label and see if the substance you are sensitive to is listed in the ingredients. Usually its the preservatives, but sometimes its the fragrances and other stuff.

I hope this is helpful to some of the folks here.

Cheers

Pete