Contact dermatitis

What is contact dermatitis?

Inflammation of the skin is commonly called ‘eczema’ or ‘dermatitis’. Contact dermatitis occurs when your skin comes into contact with something that makes it red and inflamed.

There are 2 types of contact dermatitis:

• Allergic contact dermatitis — this is caused by an allergen (a trigger). Each time you come into contact with the allergen, the skin gets inflamed.
• Irritant contact dermatitis — also known as contact dermatitis, this is when your skin gets inflamed when it’s exposed to an irritant, usually for a long period of time.

What are the symptoms of contact dermatitis?

Both types of contact dermatitis can cause the skin to become:

• cracked
• red
• blistered
• thickened
• dry
• itchy

What causes contact dermatitis?

Common causes of allergic contact dermatitis are nickel, plants, chemicals, cosmetics, creams and ointments.

Irritant contact dermatitis can be caused by frequent handwashing, medications used on the skin, cosmetics, dyes, chemicals, rubber and glues and plants.

When should I see my doctor?

You should see a doctor if you have a rash that doesn’t clear up, or if it is uncomfortable. See your doctor sooner if the rash is widespread, comes on suddenly or is painful.

How is contact dermatitis diagnosed?

If you think you have contact dermatitis, your doctor may refer you to a dermatologist (skin specialist) or immunologist (allergy specialist).

It can be difficult to diagnose the cause of allergic contact dermatitis because the rash often appears days after you come into contact with the allergen. The specialist may do a skin prick test, blood test or patch testing (when patches are applied to your skin for several days) to see what you are allergic to.

There is no specific test to diagnose irritant contact dermatitis.

How is contact dermatitis treated?

Treatment involves working out what allergen or irritant is causing the contact dermatitis and then avoiding it. The rash should clear slowly once you avoid the trigger.

It is possible to have different types of contact dermatitis at the same time. You may need to avoid several different allergens or irritants.

Your doctor may recommend a moisturiser, steroid creams or tablets, or therapy such as ultraviolet light. In severe cases, immunosuppressant medication may be needed.

Try not to scratch the affected skin and keep your nails short so you don’t accidentally scratch yourself and break the skin. Your pharmacist or doctor may be able to recommend some products which can help with dry, sore or itchy skin.

Can contact dermatitis be prevented?

If you have allergic contact dermatitis, you will be allergic to the allergen for life. Preventing the rash depends on how easy it is to avoid the trigger.

The best way to avoid an outbreak is to:

• Keep your home clear of the substance or substances that trigger the contact dermatitis.
• Take steps to protect any exposed skin if the triggers are unavoidable. Try to wear protective clothing to minimise contact, for example using gloves when washing up or using cleaning products.
• Use a barrier cream to protect your skin.
• Wash your skin as soon as you come into contact with a trigger. Also wash clothing that may have come into contact with it.
• If you come into contact with your irritants or allergens at work, tell your employer so they can help reduce any contact you have with them.
• Prevent your skin from getting too dry. Daily moisturisers (emollient creams) may help. Apply these after your skin has been wet, such as after washing up, showering or swimming.
• Avoid extreme changes in heat or cold and humidity.

Complications of contact dermatitis

Contact dermatitis can become infected. See your doctor if you have a fever or there is pus inside the blisters on your skin.