Patch Testing

Allergic Contact Dermatitis is an inflammatory reaction that occurs when substances to which you are allergic come into contact with your skin. These substances might be an ingredient in your perfume or aftershave, an antibiotic or cream, a household cleaner or something as simple as a pair of rubber boots you wear in the garden.

Patch tests are commonly used to aid in the diagnosis of allergic contact dermatitis in order to find out exactly what it is causing your skin to react.

The process involves small amounts of various allergens (the substances you may be allergic to) that are applied to distinct small squares on a larger patch which, in most cases, is applied to your back. You will wear these patches for 48 hours.

Patches must be kept dry for the 48hr duration of the test where the patient must avoid heavy exercise that makes them perspire.

The results are usually read after 48hrs and again at 72hrs after the original application of the allergens, when the allergic reactions are fully developed.

After the patches are removed your doctor will carefully examine the test area for signs of an allergic reaction. This reaction usually consists of rash with swelling, redness and tiny blisters. If you are allergic your doctor will provide information on where in the everyday surroundings you are likely to come in contact with the offending substances. You will also get advice on how to avoid these substances and your doctor can also often suggest alternatives to the items that should be avoided.

If you require patch testing, see your GP for a referral.