What is contact allergy?
Contact allergy is a sensitivity reaction of the skin which you may develop on contact with some substances usually harmless to others. These substances, or allergens as they are called, can enter your skin and causes the skin to react in a rash.
What are the most common contact allergens?
The most common allergens are nickel, (in costume jewellery), cosmetics, dye, perfumes, metals, industrial chemicals, rubber products, medicaments. You can be allergic to almost anything.
Is there a cure for contact allergy?
In many cases, removing the cause of the allergy, that is, the allergen, can relieve your symptoms. With understanding and knowledge of your problems, most sufferers from allergic conditions can lead normal lives. Contact allergy, once developed is usually life-long. The care of the allergic condition is not, however, solely a medical responsibility. Success depends on early diagnosis and co-operation between your dermatologist and you. Medication helps to relieve symptoms.
How does an allergen cause trouble?
When an allergen comes into contact with your skin, immune cells in the skin react by producing active chemical substances. These chemical substances in the skin produce inflammation resulting in an itchy rash. This sensitivity may not appear suddenly or immediately, but only after repeated exposure to the offending allergen.
How is contact allergy confirmed?
When you or your dermatologist suspects an allergy, a case history will be taken which includes information on home and work, living habits and time of years when the symptoms occur. Your dermatologist will decide from this what tests are necessary. He will then carry out skin tests which include a patch test and/or prick test to different materials, and the results of these tests together with the case history, will help him decide what treatment is needed.
PATCH TEST PROCEDURE
The patch test procedure: For detection of contact allergy
A patch test is a procedure that helps us to identify the substance you are allergic to. During the test, pieces of tapes will be plastered onto your back or shoulders.
Your co-operation is needed to ensure the successful outcome of the test. Please observe the following points:
- Leave the patches in place as instructed by the attending medical staff.
- In order to prevent false-negative results, you should not wash your back or shoulders. Avoid exposure of the test areas to sunlight or ultraviolet light. You may shower the other parts of your body.
- Avoid strenuous exercise that will cause excessive perspiration, as well as movements that may cause the patch test plasters to fall off.
- If the patch test plasters become loose, please fasten them with an additional adhesive tape in exactly the same place (and inform your doctor). The tapes are to be removed after 2 days (i.e. 48 hours later).
- If you should feel some itch, and this sometimes occurs when the test is positive, please do not scratch.
- You will need to see your dermatologist at 2 appointed dates for the reading of your test results, that is, usually 3 days and 7 days after the test patches have been plastered.
- After the patches has been removed, do remember not to wash or sunbathe the tested skin areas until after the final visit.
Should you be allergic to one or more of the substances tested, the corresponding test site(s) will develop redness and itch. This itchy rash usually disappears after a few days.
Important
- If you must use medication, even if just applied locally (ointment, creams, drops, etc), please inform your dermatologist.
- If you experience severe reaction after application of the patch test material, remove the patches and report to your dermatologist immediately.
- Should reddening of the skin or any other changes occur at the test site within 3 weeks after the final reading, please report to your dermatologist.