Patch Test

      Patch test is a process used to find allergic causes of eczema/allergic contact dermatitis to something the patient came in contact with at work or home. Patch test helps us to identify which substances may be causing a reaction in a patient.
It can produce a local allergic reaction on your back where the diluted chemicals were planted.
The chemicals included in the patch test kit are the substances in approximately 85-90 percent of contact allergic dermatitis and include chemicals present in metals (nickel), rubber, leather, cosmetic ingredients, hair dyes, formaldehyde, lanolin, fragrance, preservative and other additives.
If you know what you are allergic to you can try to avoid it, and you do not need any tests. However, some people develop dermatitis and the cause is not clear.
It is not a test to find every cause of dermatitis, but it often helps.
If the doctor diagnoses that the cause of your rash is likely to be due to allergic contact dermatitis, the doctor may tell you to come back to the skin department for patch test.
Your skin is marked to identify the location of the tests and you will be asked to keep the skin dry.

      • On the first day of test, tiny amounts of 34 substances are applied as small patches to your skin, usually on the upper back. They are fixed on with non-allergic tape.

      • After two days (on the 3rd day), you will return to the skin department and the patches are removed. The skin is examined to see if there is a reaction (red itchy areas) to any of the tested substances.

      • After a further two days (on the 5th day ) the skin is examined again in case you have a delayed reaction to any substance.