Contact Dermatitis

Let’s suppose that you were laid off in your construction job due to the decrease in housing starts. Other than the obvious change in income, you notice an interesting phenomenon: that rash on your hands and feet gradually goes away. You’re wearing jogging shoes instead of your favorite work boots, and you’re not wearing the leather gloves. What is going on here? Well, a good chance is that you’re allergic to the nickel that is used in tanning leather. When you go back to work you now wear synthetic boots and cloth gloves and, low and behold, your rash stays gone. Diagnosis: allergic dermatitis.

Let’s consider another scenario. You take a job in a photo lab because you’ve always loved photography. You start to work with a lot of solvents. You use strong detergent in the clean-up process. Your hands start to itch and turn red. The longer you work there the worse the skin condition gets. A coworker advises you to wear long latex gloves and use hand cream. Your rash gets better and eventually goes away. Diagnosis: irritant dermatitis.

One final scenario: you take lithium for control of a mood disorder. It’s always agreed with you well, and everything is going along fine. You go up to the lake one weekend, and you get a rash over all the skin areas exposed to the sun. Diagnosis: photo dermatitis. Contact dermatitis happens when a foreign substance comes in contact with the skin. In the case of photo dermatitis, ultraviolet light changes something on or in your skin, such as a drug, into a sensitizing substance.

When doctors look at this, they note a couple of facts: 1. the rash occurs where something has come into contact with the skin, 2. the longer or more often it touches the skin, the worse the rash gets. You many have been in contact with things for years. Suddenly you have a reaction for some reason. There are two kinds of substances that can cause this kind of reaction in the outer layers of the skin: one is called irritant dermatitis, and one is called allergic contact dermatitis. The allergic kind can take months or years to develop. Basically the substance has to be taken into the immune system where the body produces IgE antibodies to that substance. Then anytime after that, the body reacts to that substance with an allergic reaction. Poison ivy dermatitis is an allergic dermatitis. Joe can touch it, and the exposed areas break out into an angry red rash with blisters that can last for weeks. Fred on the other hand, can roll around in poison ivy and not get a rash. Rolling in poison ivy would not be wise because it would probably start the allergic sensitization process that would eventually head down the road to forming a rash.

There are lots of things which can sensitize and set up for a future allergic contact dermatitis. One sometimes is gold: wherever that gold jewelry touches, a rash occurs. 24k gold is pure 18, 14, 12,10k are cut with nickel. Nickel is a high allergen. The same can be true for nickel or mercury in thimerosal. Fragrances like those used in deodorants, soaps, detergents, perfumes, insecticides and pet foods can be allergens. One way to try to help identify the substances is by applying small amounts of different things in skin patch tests. This can be very helpful in helping to identify allergens affecting an individual, and advising him how to avoid them in the future.

The other type of contact dermatitis is irritant dermatitis. This is caused by things which break down the normal barriers of the skin. Some break down the natural emulsified oils which prevent water from leaving the skin. Other irritants directly affect the stratum corneum or the superficial layer of skin. Sometimes this breaks down the DNA and allows the substance to reach the deeper levels of the skin. One example is strong detergents like those used in industry. Another is solvents which can be used to thin paints and in metal-working.

We know there are a lot of things that can cause skin rashes. One type of allergic reaction is urticaria or hives. This comes on quickly and may just as quickly go away. Dermatitis may take weeks to resolve. Sometimes bacteria or viruses can cause rashes, but these are not in a contact distribution, and are most often associated with systemic symptoms.

There are treatments you can start for dermatitis. After recognizing it, go through a mental checklist of everything that has touched that area of skin and resolve to avoid it. Washing an area early of dermatitis with mild soap and water can help remove it from the skin. Cool compresses or cool oatmeal colloid baths can help. Sometimes early treatment for blisters could include calamine lotion or a skin barrier such as zinc oxide. You can buy topical cortisone cream up to 1%, and this could be something to try. You must be absolutely sure this is not shingles, measles, chicken pox, a fever blister or anything that can get worse or spread. You can buy over the counter antihistamines like Benadryl which can help the itching. It is very important not to scratch the areas as this could introduce bacteria into the rash or cause chronic skin changes like lichen simplex chronicus which are areas of leathery, tough skin. What can the doctor do? He can diagnose it and start preventative measures. He can prescribe stronger steroid creams, or steroid pills or injections. He can prescribe certain creams which help the problem but are not steroids.

So, remember, take care of your skin, and it will take care of you. If you don’t know what’s ailing your skin, then get your doctor. And, again, as is so much the case in the practice of medicine, an ounce of prevention is worth a pound of cure.

John Drew Laurusonis

Doctors Medical Center

www.doctorsmedicalctr.com