Contact dermatitis is inflammation of the skin that occurs when you come into contact with a particular substance.
It 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 caused by irritants is more common, causing up to 8 in every 10 cases.
Signs and symptoms
Contact dermatitis is a type of eczema that causes the skin to become red, blistered, dry, scaly and cracked.
This reaction will usually occur with a few hours or days of exposure to an irritant or allergen.
Symptoms can affect any part of the body, but most commonly affect the hands and face.
Seeking medical advice
You should see your GP if you have persistent, recurrent or severe symptoms of contact dermatitis. They can try to identify the cause and suggest appropriate treatments.
They can also refer you for further tests to confirm which specific irritant or allergen is causing your symptoms.
How contact dermatitis is treated
If you can successfully avoid the irritants or allergens that trigger your symptoms, your skin will eventually clear up.
However, as this isn't always possible, you may also be advised to use:
emollients – moisturisers applied to the skin to stop it becoming dry
topical corticosteroids – ointments and creams applied to the skin that can help relieve severe symptoms
oral corticosteroids – tablets that can help relieve widespread symptoms
With treatment, most people with contact dermatitis can expect their symptoms to improve, and some cases will resolve completely.
Other types of eczema
Eczema is the name for a group of skin conditions that cause dry, irritated skin. 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 – a type of eczema that occurs in circular or oval patches on the skin
varicose eczema – a type of eczema that most often affects the lower legs and is caused by problems with the flow of blood through the leg veins
Symptoms of contact dermatitis
In contact dermatitis, areas of skin directly exposed to a particular substance become red, inflamed (swollen), blistered, dry, thickened and cracked.
These symptoms can develop on any area of the body, but the hands and face are most often affected.
Symptoms caused by an irritant will usually appear within 48 hours, although strong irritants may cause your skin to react immediately, and milder irritants (such as soap and detergents) may need frequent and repeated exposure before they cause problems.
Symptoms caused by an allergen, such as make-up or metal jewellery, often take several days to develop.
If you can avoid being re-exposed to the irritant or allergen responsible for the reaction, your skin will usually clear up within a few days or weeks.
For some people, however, symptoms may be severe and long-lasting, and may affect their quality of life. For example, contact dermatitis may affect your ability to do your job and can make you feel unhappy or depressed.
Depending on the substance that has caused the reaction, you may also experience some additional symptoms.
For example, allergens may cause affected areas of the skin to itch and irritants may cause a burning or stinging sensation.
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
feeling generally unwell
having a high temperature (fever)
When to seek medical advice
You should see your GP if you have persistent, recurrent or severe symptoms of contact dermatitis. They can try to identify the cause and suggest appropriate treatments.
Seek immediate medical advice if you think your skin may have become infected, as you may need to take antibio
Causes of contact dermatitis
Contact dermatitis occurs when your skin reacts to a particular substance.
This can be either:
an irritant – a substance that damages the skin
an allergen – a substance that can cause the body to react abnormally
Irritant contact dermatitis
Irritant contact dermatitis occurs when your skin comes into direct contact with a substance that damages the outer layer of your skin, causing redness, itching, and a burning or stinging sensation.
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 are 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
oils used in machines
acids and alkalis
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:
beauticians and hairdressers
cooks and caterers
metal and electronics workers
health and social care workers
mechanics and vehicle assemblers
Allergic contact dermatitis
Allergic contact dermatitis occurs when you come into contact with a substance that causes your immune system to react abnormally.
Your immune system is the body’s natural defence system, which usually protects your body against infection and illness. During an allergic reaction, the immune system attacks healthy cells and tissue as well. This is what causes your skin to become sore and inflamed.
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 are exposed to the substance again that your skin reacts with an itchy red rash.
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 that are 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
Diagnosing contact dermatitis
Your GP can usually diagnose contact dermatitis from the appearance of your skin and by asking about your symptoms.
They will want to know when your symptoms first appeared and what substances you have been in contact with.
Identifying allergens and irritants
If your GP has diagnosed contact dermatitis, they will 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.
Your GP will look at your medical history and ask questions about your lifestyle and occupation. They may also ask whether there is 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 special kind of non-allergic tape. They may sometimes be attached to the upper arms.
After two days, the patches are removed and your skin assessed to check if there has been any reaction. Your skin will usually also be examined again after a further two days, as most allergic contact dermatitis reactions will take this long to develop.
Testing for irritants
It's very difficult to test whether specific products irritate your skin, because testing for these is very unreliable.
In some cases, a repeated open application test (ROAT) is useful, particularly to assess cosmetics. A ROAT involves reapplying the substance onto the same area of skin twice a day for 5 to 10 days, to see how your skin reacts.
This is a particularly useful way for you to check your own cosmetics at home for reactions.
Treating contact dermatitis
Treatment can help most people manage their contact dermatitis, and some people may find that their symptoms clear up entirely.
There are several ways to treat contact dermatitis, including:
reducing your exposure to irritants
These are explained below.
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 shouldn't experience any symptoms.
It's not always easy to avoid irritants or allergens that affect you, but your GP or dermatologist (a specialist in treating skin conditions) can find ways to minimise your contact with them.
If you are exposed to irritants as part of your job, wear adequate 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 are moisturising treatments applied directly to the skin to reduce water loss and cover it with a protective film. They are 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 add to bath water or use in the shower
one 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 that they contain. Ointments contain the most oil, so they can be quite greasy, but 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 red, inflamed (swollen) areas of skin. Ointments are more suitable for areas of dry skin that are not inflamed.
If you have 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 GP can prescribe 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
don't rub it in; instead, smooth it into the skin in the same direction that the hair grows
for very dry skin, apply the emollient every two to three hours
after a bath or shower, gently dry the skin and then immediately apply the emollient while the skin is still moist
If you are exposed to irritants at work that cause your contact dermatitis, make sure you apply emollients regularly during and after work.
Don't share emollients with other people.
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 GP, who can recommend an alternative product.
Be aware that some emollients contain paraffin and 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.
If your skin is very red, sore and inflamed, your GP may prescribe a topical corticosteroid (that is applied directly to your skin) which can quickly reduce the inflammation.
You may be concerned about using medication that contains steroids. However, corticosteroids are not the same as anabolic steroids, which are sometimes used (illegally) by bodybuilders and athletes. When used as instructed by your 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 topical corticosteroid for short-term use in severe contact dermatitis
a weaker topical corticosteroid if the eczema is mild
a weaker topical corticosteroid for use on your face, genitals or in the creases of your joints (such as your elbows), as your skin is thinner in these areas
a stronger topical corticosteroid 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 medication. 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 will 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 medication will usually start to have an effect within a few days. Speak to your GP if you have been using a topical corticosteroid and your symptoms have not improved.
Topical corticosteroids may cause a mild and 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
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 will increase your risk of getting side effects. For this reason, you should use the weakest and smallest amount possible to control your symptoms.
If you have a severe episode of contact dermatitis and it covers a large area of your skin, your doctor may prescribe corticosteroid tablets.
You may be prescribed corticosteroid tablets to take for five to seven days. Depending on how effective this is, your dose may then be may gradually reduced over two to three weeks.
If corticosteroid tablets are taken often or for a long time, they can cause a number of side effects, such as:
reduced growth rate in children
high blood pressure (hypertension)
osteoporosis (brittle bones)
For this reason, your doctor is unlikely to prescribe repeat courses of corticosteroid tablets without referring you to a specialist.
If the treatments prescribed by your 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 your dermatologist include:
phototherapy – where the affected area of skin is exposed to ultraviolet (UV) light to help improve its appearance
immunosuppressant therapy – medicines that reduce inflammation by suppressing your immune system
alitretinoin – a type of oral medication licensed for severe eczema affecting the hands
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 your GP first to make sure the therapy is safe for you to use. You should continue to use any other treatments prescribed by your GP.
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.
Clean your skin
If you come into contact with an allergen or irritant, rinse the affected skin with warm water and a soap substitute (an emollient – see below). Do this as soon as possible after coming into contact with the allergen or irritant.
Use protective clothing
You can wear protective clothing to reduce your contact with the allergens or irritants.
Irritant contact dermatitis often affects the hands, so gloves are an easy and effective way of minimising your contact with an irritant. You may find it useful to wear cotton gloves underneath rubber gloves, if the rubber also irritates you. Take your gloves off every now and again, as sweating can make any symptoms worse.
If you work with potential irritants, there may be health and safety guidance at work that tells you about the protective equipment you should wear.
If you know that a certain product causes your contact dermatitis, such as a type of make-up or soap, try using a different product.
Check the ingredients 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.
Apply emollients frequently and in large amounts (read about how contact dermatitis is treated for more information). These will keep your skin hydrated and help protect it from allergens and irritants.
Use emollient soap substitutes rather than regular bar or liquid soaps, as these can dry out your skin. This is particularly important if you need to wash your hands frequently at work.
Barrier creams can be applied to create a barrier between you and the irritant. If used correctly, they may help reduce contact with the irritant. However, it's not clear how effective they are, so you shouldn't rely on them as your only form of protection. A physical barrier is much better protection.
After-work creams are designed to be used at the end of your working day. Applying after-work creams may reduce the frequency and severity of your symptoms.
Rare cases of contact dermatitis are caused by the allergen nickel, which is found in very small amounts in certain foods such as lentils, nuts and oats.
There is limited evidence that people who are sensitive to nickel might benefit from following a diet low in nickel, but you should speak to your doctor before making any changes to your die