Contact dermatitis: treatment, causes, symptoms and how long it lasts

The NHS says that if the substance causing your contact dermatitis can be identified and avoided, your symptoms should improve and may even clear up completely. A pharmacist can recommend emollients (moisturisers) and, where that is not enough, a GP may prescribe stronger treatment.

Contact dermatitis is where the skin reacts to substances it has come into contact with. The British Association of Dermatologists (BAD) says dermatitis, also known as eczema, means inflammation of the skin, and that contact dermatitis is common and can have a long-term impact on daily activities and emotional wellbeing.

NICE CKS describes it as an inflammatory skin reaction to an external irritant or allergen. Acute contact dermatitis typically shows redness and small blisters, and chronic disease typically shows dryness, thickening of the skin and fissuring.

No. BAD says contact dermatitis is not contagious and cannot spread from person to person. It is a reaction of your own skin to a substance.

The exception is infection of broken skin. BAD says a bacterial infection of contact dermatitis may lead to impetigo, which is very contagious and needs treatment from a healthcare provider. The NHS lists signs of infection as symptoms rapidly getting worse, discharge from the skin, increasing pain, feeling generally unwell and feeling hot, cold or shivery.

The NHS says 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. The reaction usually occurs within a few hours or days of exposure.

For irritant contact dermatitis, the NHS says symptoms can appear straight away or up to 48 hours after exposure, and range from mild dryness, redness, burning or stinging to very painful blisters that fill with fluid. Allergic contact dermatitis mainly affects the hands, and symptoms range from mild redness and itchiness to cracked, fluid-filled, extremely itchy skin with a stinging sensation, appearing immediately or after a delay.

The NHS says 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. The first time you come into contact with an allergen, your body becomes sensitised without reacting; it is only on re-exposure that the immune system causes the skin to become red and itchy.

It depends on whether the trigger can be found and avoided. The NHS says that if you can avoid or reduce exposure, you should not experience symptoms, and BAD says avoiding an allergen confirmed by patch testing can lead to significant improvement or even complete clearance.

BAD also says it may take several months for contact dermatitis to settle, that completely avoiding some triggers can be challenging, and that continued contact with the trigger will make it worse. It says there is no cure, but the condition can be prevented and managed by identifying and avoiding triggers.

The NHS says a GP can usually diagnose contact dermatitis from the appearance of your skin and by asking about your symptoms, what substances you have been in contact with, your lifestyle and occupation, and whether there is a family history of dermatitis or eczema.

If allergens or irritants cannot be identified, or the trigger is known but symptoms are not responding, you may be referred to a dermatologist. The best way to test for an allergic reaction is patch testing: tiny amounts of known allergens are attached to your back with non-allergic tape, removed after 2 days, and the skin checked, then examined again after a further 2 days because most allergic reactions take this long to develop. BAD says patch testing is carried out in a specialist dermatology department.

The NHS says 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 reduce the risk:

• If you come into contact with an allergen or irritant, rinse the affected skin with warm water and an emollient as soon as possible.

• Use gloves to protect your hands, but take them off every now and again, as sweating can make symptoms worse; cotton gloves under rubber gloves may help.

• Change products that irritate your skin and check the ingredients of make-up or soap.

• Apply emollients frequently and in large amounts, and use emollient soap substitutes rather than regular soap.

• If exposed to irritants at work, tell your employer about your condition so they can help you avoid the causes, and use emollients regularly during and after work.

The NHS says you may be more at risk if you work with irritants or your job involves a lot of wet work, and lists 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, and mechanics.

NICE CKS says contact dermatitis associated with occupation should be considered for dermatology referral, and that employers have a legal duty to report a case of occupational skin disease to the Health and Safety Executive and to assess and control risks at work.

The NHS says to speak to a pharmacist if contact dermatitis is troubling you, and to see a GP if you have persistent, recurrent or severe symptoms. A GP may refer you to a dermatologist if the substance cannot be identified or symptoms are not responding to treatment.

The NHS says to seek immediate medical advice if you have a severe reaction, or you think your skin may have become infected, as you may need antibiotics. You can call 111 or use 111 online. If you stop a topical steroid and develop intense redness and swelling of the skin, call 111 for advice immediately.

Most contact dermatitis is managed by a pharmacist or GP, with referral to NHS dermatology for patch testing or persistent disease.

Some people choose a private dermatologist for faster assessment or patch testing. Ask what allergens are included in a patch test series and how results will be shared with your GP, since avoiding the right allergen is the main treatment.