An allergic reaction caused by the skin's contact with a substance that is usually harmless to others is called contact allergy. You may suddenly become allergic to a substance that you have used all your life. Allergy occurs within 48 hours of contact with the allergen substance. The part of the skin that contacts the allergen becomes itchy and red and develops vesicles. Sometimes swelling, weeping, and blistering may also occur.



The rash can spread to other parts of the body. However, this happens rarely. Sometimes it takes months or weeks for the allergy to heal, because the allergic substance stays in contact constantly. Allergic contact dermatitis is the term given to rashes occurring due to contact allergy. Usually adults face the problem of allergic contact dermatitis. It mostly occurs from contact with poison ivy and poison oak.

Substances Causing Contact Allergy

Generally, harmless substances cause contact allergy. Metals like nickel and chrome, skin care products comprising fragrances and lanoline, and certain medications cause contact allergy. A patch test carried under the surveillance of a physician confirms the occurrence of contact allergy. Patch test is carried out on the upper back of the person's body. A simultaneous testing of several allergens is done and the results are obtained within 48 to 96 hours. Once a person develops allergy to a particular substance it stays for life.

Treatment Available

The available treatment varies by the type of rash or allergy. It is recommended in all cases, however, to stop using all products on the exposed area. Use only the treatment prescribed by the dermatologist. Usually the dermatologist prescribes a cortisone ointment preparation. Because it is a strong medication, use it initially for a week then visit your dermatologist and have the allergy checked. Follow what your doctor says.

Usually it takes two weeks for the allergy to subside. After the healing period is over search for the chemical/substance you are allergic to. Do this by repeating the use of all products you used priory. Use them one at a time with a gap of one week between uses of each product. This way you will easily detect the allergic product. Avoid using this particular chemical/substance in the future. However, when unable to determine the cause, certain patch tests may help to obtain precise and detailed results.

If you are thinking that allergy is only a simple disease, you may be quite wrong. You may be afflicted by only one or two types of allergies. This may lead you to feel that allergies are limited to only those types. However, if you take a look around and see other people suffering from various other allergies you will soon realize that allergies are definitely not as simple as they sound. You will be flabbergasted to know the variety of the types of allergies that occur.

Allergies can be roughly classified under three different categories. Almost all the varied kinds of allergies may be place under them. Let us take a look at the three different categories and the types that come under them.