Diagnosis - Contact dermatitis

Your GP can usually diagnose contact dermatitis from symptoms and signs on your skin.

Your GP may ask you:

• when your symptoms appeared
• what substances you were in contact with
• if other people in your family have dermatitis

Identifying allergens and irritants

Your GP may ask about your medical history, lifestyle and job. The questions can help identify if you are in contact with any allergens or irritants.

If you can avoid those substances, you can reduce the risk of having symptoms. Avoiding hand soap or fragranced bath products can help if do not know what causes your symptoms yet.

Your GP may refer you to a dermatologist (skin specialist) if:

• they think an allergy may cause your symptoms
• you cannot identify the cause of your contact dermatitis
• your symptoms do not improve with treatment

Testing for allergens

A patch test can show a reaction to allergens. The test involves putting a special tape on your skin. The tape contains patches of different allergens.

A dermatologist who specialises in skin allergies usually does the patch test.

1. The tester puts the test tape on your back. Sometimes they may put the tape on your tummy or upper arm.
2. After a few days, the tester removes the tape and checks your skin for any reactions.
3. After another few days, the tester checks your skin again - some reactions take longer to develop.

During the test period, you must keep the area dry and avoid:

• showers and baths
• sweating a lot

Testing for irritants

It's difficult to test if specific products irritate your skin. Testing for irritants is unreliable.

You can identify an irritant as a cause if your symptoms improve after you avoid contact with that irritant.