Contact dermatitis

Contact dermatitis is a type of eczema triggered by contact with a particular substance.

Eczema is the name for a group of conditions that cause skin to become dry and irritated.

Contact dermatitis usually improves or clears up completely if the substance causing the problem is identified and avoided. Treatments are also available to help ease the symptoms.

Symptoms of contact dermatitis

Contact dermatitis causes the skin to become itchy, blistered, dry and cracked.

Lighter skin can become red, and darker skin can become dark brown, purple or grey.

This reaction usually occurs within a few hours or days of exposure to an irritant or allergen.

Symptoms can affect any part of the body but most commonly the hands and face.

Read about symptoms of contact dermatitis

When to see a pharmacist

Speak to a pharmacist if your contact dermatitis is troubling you.

They can recommend treatments such as emollients (moisturisers), which you rub on your skin to stop it becoming dry.

When to see a GP

See a GP if you have persistent, recurrent or severe symptoms of contact dermatitis. They can try to identify the cause and suggest appropriate treatments.

A GP may refer you to a doctor who specialises in treating skin conditions (dermatologist) for further tests if:

• the substance causing your contact dermatitis cannot be identified
• your symptoms are not responding to treatment

Read about diagnosing contact dermatitis

Causes of contact dermatitis

Contact dermatitis can be caused by:

• an irritant – a substance that directly damages the outer layer of skin
• an allergen – a substance that causes the immune system to respond in a way that affects the skin

Contact dermatitis is most commonly caused by irritants such as soaps and detergents, solvents or regular contact with water.

Allergic contact dermatitis is less common and can be triggered by an allergic reaction to substances found in certain products, such as cosmetics, or some metals, including nickel.

Handling raw, uncooked fruit and vegetables may also trigger allergic contact dermatitis in some people.

Read about causes of contact dermatitis

Treating contact dermatitis

If you can successfully avoid the irritants or allergens that trigger your symptoms, your skin will eventually clear up.

However, as this is not always possible, you may also be advised to use:

• emollients – moisturisers applied to the skin to stop it becoming dry
• topical corticosteroids – steroid ointments and creams applied to the skin to relieve severe symptoms

If you have a severe episode of contact dermatitis and it covers a large area of your skin, a doctor may prescribe oral corticosteroids, but this is rare.

Read about treating contact dermatitis

Preventing contact dermatitis

The best way to prevent contact dermatitis is to avoid contact with the allergens or irritants that cause your symptoms.

If you cannot avoid contact, you can take steps to reduce the risk of the allergens or irritants causing symptoms, including:

• cleaning your skin – if you come into contact with an allergen or irritant, rinse the affected skin with warm water and an emollient as soon as possible
• using gloves to protect your hands – but take them off every now and again, as sweating can make any symptoms worse; you may find it useful to wear cotton gloves underneath rubber gloves if the rubber also irritates you
• changing products that irritate your skin – check the ingredients on make-up or soap to make sure it does not contain any irritants or allergens; in some cases, you may need to contact the manufacturer or check online to get this information
• applying emollients frequently and in large amounts – these keep your skin hydrated and help protect it from allergens and irritants; you could also use emollient soap substitutes rather than regular bar or liquid soaps, which can dry out your skin

Other types of eczema

Other types of eczema include:

• atopic eczema (also called atopic dermatitis) – the most common type of eczema; it often runs in families and is linked to other conditions, such as asthma and hay fever
• discoid eczema – circular or oval patches of eczema on the skin
• varicose eczema – this most often affects the lower legs; it's caused by problems with the flow of blood through the leg veins

 Symptoms Contact dermatitis 

Contact dermatitis affects the skin. The type of skin symptoms you get can depend on whether the dermatitis is caused by an irritant or an allergic reaction.

Symptoms of irritant contact dermatitis

The symptoms of irritant contact dermatitis can appear straight away after you are exposed to the irritant or may not appear until within 48 hours after exposure.

The symptoms can range from mild dryness, redness, burning or stinging of the skin to very painful blisters that can become filled with fluid.

Symptoms of allergic contact dermatitis

The symptoms of contact dermatitis can appear immediately after exposure or there may be a delayed reaction, depending on the type of allergy you have.

Allergic contact dermatitis mainly affects the hands.

The symptoms can range from mild redness and itchiness of the skin to skin that becomes cracked, filled with fluid, extremely itchy and has a stinging sensation.

Symptoms of infection

Occasionally, areas of skin affected by contact dermatitis can become infected. Signs of an infection can include:

• your existing symptoms getting rapidly worse
• discharge from your skin
• increasing pain
• feeling generally unwell
• feeling hot or shivery

Seek immediate medical advice if you have a severe reaction, or you think your skin may have become infected, as you may need to take antibiotics.

 Causes Contact dermatitis 

Contact dermatitis occurs when your skin reacts to a particular substance.

This can be either:

• an irritant – a substance that directly damages the outer layer of skin
• an allergen – a substance that causes your immune system to respond in a way that affects the skin

Irritant contact dermatitis

Irritant contact dermatitis may be caused by frequent exposure to a weak irritant, such as soap or detergent. It may also develop if you've been in contact with a stronger irritant for a short while.

You're at an increased risk of irritant contact dermatitis if you also have atopic eczema, which is the most common form of eczema. 

Common irritants include:

• soaps and detergents
• antiseptics and antibacterials
• perfumes and preservatives in toiletries or cosmetics
• solvents
• oils used in machines
• disinfectants
• acids and alkalis
• cement
• powders, dust and soil
• water – especially hard, chalky water or heavily chlorinated water
• many plants – such as Ranunculus, spurge, Boraginaceae and mustards

If you already have irritant contact dermatitis symptoms, they can be made worse by heat, cold, friction (rubbing against the irritant) and low humidity (dry air).

Exposure at work 

You may be more at risk of irritant contact dermatitis if you work with irritants as part of your job, or if your job involves a lot of wet work.

If you develop the condition because of a substance you work with, it may be referred to as occupational irritant dermatitis.

This type of dermatitis is more common in certain occupations, including:

• agricultural workers
• beauticians and hairdressers
• chemical workers
• cleaners
• construction workers
• cooks and caterers
• metal and electronics workers
• health and social care workers
• machine operators
• mechanics and vehicle assemblers

Allergic contact dermatitis

The first time you come into contact with an allergen, your body becomes sensitised to it, but does not react to it. It's only when you're exposed to the substance again that your immune system reacts and causes the skin to become red and itchy.

Allergens that commonly cause allergic contact dermatitis include:

• cosmetic ingredients – such as preservatives, fragrances, hair dye and nail varnish hardeners
• metals – such as nickel or cobalt in jewellery
• some topical medicines (medicines applied directly to the skin) – including topical corticosteroids, in rare cases
• rubber – including latex, a type of naturally occurring rubber
• textiles – particularly the dyes and resins that are contained in them
• strong glues – such as epoxy resin adhesives
• some plants – such as chrysanthemums, sunflowers, daffodils, tulips and primula

 Diagnosis Contact dermatitis 

A GP can usually diagnose contact dermatitis from the appearance of your skin and by asking about your symptoms.

They'll want to know when your symptoms first appeared and what substances you've been in contact with.

Identifying allergens and irritants

If a GP has diagnosed contact dermatitis, they'll try to identify what has triggered your symptoms. If the allergens or irritants can be identified, you can take steps to avoid those substances and reduce the risk of your symptoms flaring up.

A GP will look at your medical history and ask questions about your lifestyle and occupation. They may also ask whether there's a history of dermatitis or eczema in your family.

Referral to a specialist

If the allergens or irritants causing your contact dermatitis cannot be identified, you may be referred to a dermatologist (a doctor who specialises in treating skin conditions).

You may also be referred to a dermatologist if the trigger has been identified, but your symptoms are not responding to treatment.

Testing for allergens

The best way to test for a reaction to allergens is by patch testing. During a patch test, tiny amounts of known allergens are applied to your skin.

The substances are attached to your back using a kind of non-allergic tape. They may sometimes be attached to the upper arms.

After 2 days, the patches are removed and your skin assessed to check if there has been any reaction.

Your skin will usually be examined again after a further 2 days, as most allergic contact dermatitis reactions take this long to develop.

 Treatment Contact dermatitis 

If the substance causing your contact dermatitis can be identified and avoided, your symptoms should improve and may even clear up completely.

There are a number of treatments to help ease your symptoms if it's not possible for you to avoid the substance causing them.

A pharmacist will be able to recommend treatments like emollients (moisturisers), which you rub on your skin to stop it becoming dry.

Find your nearest pharmacy

Avoiding the cause

One of the most important steps in treating contact dermatitis is identifying and avoiding the allergens or irritants that affect you. If you can successfully avoid or reduce your exposure to the cause, you should not experience any symptoms.

It's not always easy to avoid irritants or allergens that affect you, but a pharmacist, GP or dermatologist (skin specialist) can suggest ways to minimise your contact with things that trigger your condition.

If you're exposed to irritants as part of your job, wear protective clothing to minimise any contact. Tell your employer about your condition, so they can help you avoid the causes as much as possible.

Emollients

Emollients are moisturising treatments applied directly to the skin to reduce water loss and cover it with a protective film. They're often used to help manage dry or scaly skin conditions such as eczema.

Choice of emollient

Several different emollients are available. You may need to try a few to find one that works for you. You may also be advised to use a mix of emollients, such as:

• an ointment for very dry skin
• a cream or lotion for less-dry skin
• an emollient to use instead of soap
• an emollient to use on your face and hands, and a different one to use on your body

The difference between lotions, creams and ointments is the amount of oil they contain. Ointments contain the most oil so can be quite greasy, but they are the most effective at keeping moisture in the skin. Lotions contain the least amount of oil so are not greasy but can be less effective. Creams are somewhere in between.

Creams and lotions tend to be more suitable for inflamed (swollen) areas of skin. Ointments are more suitable for areas of dry skin that are not inflamed.

If you've been using a particular emollient for some time, it may eventually become less effective or may start to irritate your skin. If this is the case, your pharmacist can recommend another product.

How to use emollients

Use your emollient frequently and in large amounts. Many people find it helpful to keep separate supplies of emollients at work or school.

To apply the emollient:

• use a large amount
• do not rub it in – smooth it into the skin in the same direction the hair grows
• for very dry skin, apply the emollient 2 to 4 times a day, or as prescribed by a doctor
• after a bath or shower, gently dry the skin and then immediately apply the emollient while the skin is still moist

If you're exposed to irritants at work that cause your contact dermatitis, make sure you apply emollients regularly during and after work.

Do not share emollients with other people.

Side effects

Occasionally, some emollients can irritate the skin. If you have contact dermatitis, your skin will be sensitive and can sometimes react to certain ingredients, such as perfume in over-the-counter emollients.

If your skin reacts to the emollient, stop using it and speak to your pharmacist, who may be able to recommend an alternative product.

Be aware that some emollients can be a fire hazard, so should not be used near a naked flame. Emollients added to bath water can make your bath very slippery, so take care getting in and out of the bath.

Topical corticosteroids

If your skin is also sore and inflamed, a GP may prescribe a topical corticosteroid (a cream or ointment applied directly to your skin) that can quickly reduce the inflammation.

When used as instructed by a pharmacist or doctor, corticosteroids are a safe and effective treatment for contact dermatitis.

Choice of topical corticosteroid

Different strengths of topical corticosteroids can be prescribed, depending on the severity of your contact dermatitis and where the affected skin is.

You may be prescribed:

• a stronger cream for short-term use for severe contact dermatitis
• a weaker cream for use on thinner areas of your skin, such as your face or neck
• a stronger cream to use on your palms and the soles of your feet, as the skin is thicker here

How to use topical corticosteroids

When using corticosteroids, apply the treatment in a thin layer to all the affected areas. Unless instructed otherwise by your doctor, follow the directions on the patient information leaflet that comes with your medicine. This will give details of how much to apply.

During an episode of severe contact dermatitis, do not apply the corticosteroid more than twice a day. Most people only have to apply it once a day.

You should apply your emollient first and wait around 30 minutes before applying the topical corticosteroid.

The medicine will usually start to have an effect within a few days. Speak to a GP if you've been using a topical corticosteroid and your symptoms have not improved.

Side effects

Topical corticosteroids may cause a mild, short-lived burning or stinging sensation as you apply them. In some cases, they may also cause:

• thinning of the skin
• changes in skin colour
• acne (spots)
• increased hair growth

Most of these side effects will improve once treatment stops.

Generally, using a stronger topical corticosteroid or using a large amount of topical corticosteroid increases your risk of getting side effects. You should use the weakest and smallest amount possible to control your symptoms and never use more than the amount recommended by your doctor.

Sometimes people may also develop skin symptoms after they stop using a steroid cream, such an intense redness and swelling of the skin. If this happens to you then call 112 for advice immediately.

Steroid tablets

If you have a severe episode of contact dermatitis and it covers a large area of your skin, a doctor may prescribe corticosteroid tablets. But this is rarely needed.

If steroid tablets are taken often or for a long time, they can cause a number of side effects, such as:

• high blood pressure (hypertension)
• osteoporosis (brittle bones)
• diabetes

For this reason, a doctor is unlikely to prescribe repeat courses of corticosteroid tablets without referring you to a specialist.

Further treatments

If the treatments prescribed by a GP are not successfully controlling your symptoms, they may refer you for assessment and treatment by a dermatologist.

Further treatments that may be available from a dermatologist include:

• immunosuppressant therapy – medicines that reduce inflammation by suppressing your immune system
• alitretinoin – capsules licensed for severe eczema affecting the hands
• phototherapy – where the affected area of skin is exposed to ultraviolet (UV) light to reduce inflamation

Complementary therapies

Some people may choose to use complementary therapies for contact dermatitis, such as food supplements or herbal remedies, but there is often a lack of evidence to show they are effective in treating the condition.

If you are thinking about using a complementary therapy, speak to a GP first to make sure the therapy is safe for you to use. You should continue to use any other treatments prescribed by a GP.