Contact dermatitis

What is contact dermatitis?

There are 2 types of contact dermatitis – irritant and allergic contact dermatitis.

Irritant contact dermatitis

• Occurs when your skin comes into contact with an irritant substance

• The irritating or toxic substance directly causes a reaction with your skin and damages the outside layer of the skin

Allergic contact dermatitis

• Occurs when your skin comes into contact with a substance that you’re allergic to

• Your immune system mounts a reaction to the substance causing a typically itchy rash

What are the symptoms of contact dermatitis?

If you have contact dermatitis you might have some of the following skin symptoms:

• Dry and scaly areas of skin

• Itching

• Blisters that may ooze

• Burning

• Tightness

The symptoms are usually localised to the area of skin which has come into contact with the allergen or irritant substance. It can occur on any part of the body.

Contact dermatitis is common on the face. Sometimes it can be difficult to work out what has caused the rash but it’s often down to cosmetics or personal-care products.

What causes contact dermatitis?

The best way to work out the cause of your contact dermatitis is to look at the area of skin affected. Is the rash in a particular pattern or area? Has that area of skin been in contact with an irritant substance or allergen?

There are many causes of contact dermatitis, and here are just a few of them.

Irritants that commonly cause contact dermatitis:

• Detergents

• Regular contact with water

• Solvents

• Soap

Allergens that commonly cause contact dermatitis:

• Preservatives and fragrances in cosmetics

• Nail varnish hardener

• Hair dye

• Jewellery

How is contact dermatitis diagnosed?

Contact dermatitis can be diagnosed by a GP who will look at your skin and ask you about the symptoms you’ve been experiencing.

If there’s no obvious cause for your contact dermatitis, the doctor may need to do patch testing. This is where small amounts of substances that you might be allergic to are applied to the skin on your back.

After a few days, the patches are removed and the doctor will check your skin to see if any of the known substances have caused a reaction. 

How to treat contact dermatitis

Contact dermatitis treatment involves firstly avoiding contact with the substance that has caused the skin reaction.

A pharmacist can give you an emollient cream to apply to the affected skin. This acts as a moisturiser and can help to repair the skin barrier, as well as reducing water loss from the skin.

You may also be given a steroid cream that can be applied to the area of contact dermatitis to help reduce inflammation.

When should I seek help?

If you think that you might have contact dermatitis you should speak to a doctor or pharmacist who can recommend treatments, such as emollients, that you apply to your skin.

If your contact dermatitis keeps coming back or does not resolve with over the counter treatments, make sure you see a GP.

Occasionally, areas of contact dermatitis might become infected. Increasing pain around the area, discharge, fever or feeling generally unwell might indicate that you have an infection, and should seek help from a GP or call NHS 111 immediately.

If your contact dermatitis is particularly severe or keeps coming back, a GP might refer you to a dermatologist. A dermatologist is a specialist doctor that deals with skin conditions and can help to find an appropriate treatment and determine the cause of your contact dermatitis.