Allergic Contact Dermatitis


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Allergic contact dermatitis is when an allergic reaction occurs when the skin comes into contact with a material that causes the release of histamines and can cause an itchy skin condition which is often very uncomfortable. It can arise fairly quickly after contact or take several hours or even days to appear. As is the case with many allergic responses, the initial skin contact with a potential allergen may result in no reaction at all. However, the skin will have become sensitised by this contact and subsequent contacts with the allergen will result in an allergic reaction.

Symptoms of Allergic Contact Dermatitis

Symptoms of allergic contact dermatitis vary depending on the circumstances, but most often include a reddening of the skin coupled with some swelling and possibly blisters. If the blisters are scratched and broken, the skin may become crusty and take on a scale like appearance. It is important to see your GP if you think you may have allergic contact dermatitis as it can be tricky to tell the difference between this and other non allergic type rashes. Once it is established that the rash is from an allergic response, your GP can perform a simple series of patch tests. These tests involve the application of small amounts of different suspect allergens to the skin for a few days. Any positive patches will result in an allergic response. Listed below are some of the more common skin allergens:

Nickel Allergy

This is found in various metal products such as jewellery, snaps, zips, hair clips and needles. Nickel sensitive individuals should avoid any products that may contain this compound. For some people, an allergic reaction to nickel can be intensified if they are perspiring. In the heat of the summer, sweat reacts with the nickel to cause an increased allergic response.

Dyes Allergy

There is an ingredient in the majority of permanent hair dyes called paraphenylenedeamine(PPDA). If applied to the scalp of a sensitive person, it becomes red, itchy and painful. In some cases the hair follicles are weakened to such a degree that hair loss occurs. PPDA is also used in some clothing dyes, although not very often. In this instance, many find that the darker the clothing the more sensitive to the dye they are and the stronger the allergic reaction.

Rubber Latex Allergy

The major sources of rubber allergies lye in latex gloves, clothing and footwear. With gloves there is often an instant reaction with symptoms including burning, itching and swelling under the latex. Many companies now produce latex free gloves for those affected. This is especially important for health care providers and scientists whom often spend a large amount of time with gloves on for protection. In individuals sensitive to rubber, clothing and footwear can often present a challenge as rubber is found in a wide variety of products. Bras and underwear, trousers, shirts and varying aspects of shoes can all have rubber incorporated in to their design. Fortunately, substitutes are readily available.

Plants Allergy

Some plants such as poison oak and poison ivy can cause a very uncomfortable red, itchy rash with fluid filled blisters. If the blisters are scratched and the liquid inside comes into contact with other areas of the skin the rash can spread.

Chromates Allergy

These are intensely potent oxidising agents that are commonly used in the chemical, building, automobile and industrial trades. For individuals sensitive to chromium (found in all chromates), care must be taken when handling all products that may contain this compound. Sources can include building and auto supplies, the tips of matches, paints and even some leather products. If contact does occur, a painful swollen rash can occur.

As with all allergic contact dermatitis, once the allergen is removed the skin will usually quieten down and return to normal.


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