Dermatitis: what causes it and how to treat it
If you’re over 60 and you’ve started experiencing inflamed and itchy skin for the first time in your life, this could be the onset of atopic dermatitis. Considered in the past to be primarily a children’s condition, atopic dermatitis – the most common form of eczema – can affect people of all ages, and according to data from a British Journal of Dermatology review, it is now almost as common in adults over 60 as it is in children under 18.
There’s no cure for this chronic inflammatory skin disease which affects about two per cent of the global population, causing itchy, rough and cracked patches of skin. But reports from a clinical trial of rocatinlimab – a monoclonal antibody therapy – for the treatment of moderate to severe atopic dermatitis has shown promising results, although it’s not yet available for use.
Contrary to popular belief, dermatitis is not contagious, but it can be chronic, so living with the condition means finding the right way to manage your “flares” when they occur. There are many separate conditions that fall under the term dermatitis, so here are the facts on symptoms for each type and expert advice on the best way to manage them.
What is dermatitis?
“Dermatitis is a medical term for rash,” says Dr Zainab Laftah, consultant dermatologist and British Skin Foundation spokesman. It refers to when the skin becomes red, sore and irritated. One cause is atopic eczema, but it is a term that also refers to a rash caused by an external agent or allergic reaction.
Dermatitis symptoms
There are a whole range of symptoms, depending on the type of dermatitis in question. Itchiness, blisters, a rash and dry, cracked, scaly skin can be seen in all skin types, with small bumps more typical in darker skin.
“Most people with dermatitis will get an eczema-like reaction,” says Dr Laftah. “So that is basically redness, sometimes bumps, often scaling with associated itching. And then, depending on the type of dermatitis and its underlying cause, sometimes you can get pimples or pustules, and in the case of allergic contact dermatitis you can get blisters. With seborrheic dermatitis, it can be red patches and scales.”
Dermatitis causes
There are many different causes of dermatitis, depending on the type. “Seborrheic dermatitis presents as flaking and redness of the skin in eyebrows and nasolabial folds, often in people with greasy skin, and can be worse with stress and a stressful lifestyle,” says Dr Susan Mayou, consultant dermatologist at the Cadogan Clinic.
With chronic irritation like seborrheic dermatitis, as well as stress, illness can also trigger flares. “And we know that irritant and contact dermatitis is much greater in the winter months because of the cold and central heating drying out the skin,” says Dr Laftah.
These skin conditions seem to work in clusters, she adds. “With patients who have a history of eczema, their risk of allergic contact dermatitis is about three to five per cent, so slightly higher than those who don’t. And with irritant contact dermatitis the barrier function is slightly suboptimal in comparison with someone who doesn’t have a history of eczema. With people who have eczema or psoriasis running in the family, or have it themselves, the risk of seborrheic dermatitis is also higher.”
Ageing alone may also result in pathophysiologic changes that could trigger or worsen atopic dermatitis, and older skin is dryer, with the skin barrier weakening with age, so the itch can be far worse than for younger skins.
Types of dermatitis:
Seborrheic dermatitis
Seborrheic dermatitis is a type of hypersensitivity reaction caused by the yeast Malassezia which lives on our skin and scalp as part of our natural skin flora. “Some people develop a hypersensitivity reaction to the yeast that basically breaks down oil into a metabolite which irritates their skin,” says Dr Laftah. “Typically, patients will have dandruff and a dry red scaly scalp, with similar changes around the eyebrows, nostrils, armpit, groin and, in men, on the beard and chest – areas where you typically get lots of hair follicles with oil glands.” It can also appear under the breasts in women. In infants it’s known as “cradle cap” and typically resolves on its own.
But in adults it can be more persistent. “It’s a condition that’s linked to stress, which explains why it tends to improve when you go on holiday,” says Dr Mayou.
While you can suppress seborrheic dermatitis, it can’t be eradicated. Instead, it’s a matter of maintenance, says Dr Laftah. “As the yeast is always going to be part of our natural flora, keeping those levels under control by using medicated shampoo is vital,” she says. Steroid shampoos or scalp applications will suppress the inflammation. Elsewhere on the body, treatment is different.
“In mild cases it can be managed with moisturisers but at the next level of severity where there’s redness as well (erythema), we would prescribe Daktacort, which is a combination of one per cent hydrocortisone with an anti-yeast agent,” says Dr Mayou.
Contact dermatitis
There are two types of contact dermatitis – irritant and allergic. Allergic contact dermatitis is a type of allergy to products that come into contact with the skin, causing blistering, bumps, redness and scaling. “It can be a reaction to metal, rubber, acrylics, perfumes and parabens in products. Commonly the allergen in contact allergy is nickel, perfume or preservatives,” says Dr Laftah.
“Irritant dermatitis is very common in young mums and hairdressers, people who have their hands in water a lot which compromises the skin barrier, and as a result you get dryness which, if left untreated, progresses to redness and cracking which can lead to infection,” says Dr Mayou.
Unlike a true allergic contact allergy, an irritant contact allergy is not related to the immune system, but caused by a skin barrier dysfunction when it’s damaged by an irritant. “Washing your hands typically can result in contact allergy because you’re stripping away the natural oil, rendering the skin barrier suboptimal and therefore you can get dermatitis on your hands because of over washing, for example,” says Dr Mayou. The worldwide prevalence of contact dermatitis has been estimated at approximately 20 per cent of the general population, with 80 per cent of these cases being irritant contact dermatitis and 20 per cent being allergic. Occupational contact dermatitis is common, with beauticians, cooks, florists, barbers and hairdressers particularly affected, and contact with soaps and cleaning products and working with wet hands (“wet work”) are the most commonly recorded causes.
“The approach to treatment is first to restore the skin’s barrier by using a soap substitute and applying an appropriate moisturiser frequently. If that on its own isn’t enough and the skin remains inflamed then we add in a topical steroid,” says Dr Mayou.
Perioral dermatitis
Perioral dermatitis is a skin disorder which presents as redness and flaking, or tiny spots around the mouth,” says Dr Mayou. If it doesn’t respond to Daktacort, which is the usual first-line treatment, then antibiotics are often prescribed. “We use the same antibiotic as prescribed for acne, not because these pustules are infected, but for their anti-inflammatory role,” says Dr Mayou.
“There’s a higher incidence of perioral dermatitis in women and those who are between 20 to 40 years old, and there’s likely to be a hormonal component to this barrier dysfunction,” says Dr Laftah. It also seems to affect people with a lighter skin tone. “Some people can develop it using very harsh products, and we urge them to avoid [products containing] retinoids and acids,” she adds.
Atopic dermatitis
The most common form of eczema, this type of dermatitis has a genetic component, with children who have family with the condition more likely to develop it too, although it can affect people of all ages. People who have asthma and/or hay fever, or have family members who do, are more likely to develop atopic dermatitis. It is the most common type of eczema in children, often developing before their first birthday.
Common triggers include shampoo, washing-up liquid and bubble bath, as well as cold and dry weather and dampness. It can also be triggered by specific things like dust mites, pets, pollen and moulds. While symptoms vary, they include itchy, flaky patches of skin that can turn red and weepy or crusty.
The main treatments are emollients (moisturisers), used regularly to prevent dryness, with topical corticosteroids in the form of creams and ointments used to reduce swelling and redness during flares. “If you have a compromised skin barrier, even the preservatives in a cream moisturiser or steroid cream can sting,” says Dr Mayou. “Some people think this means they’re allergic to the cream but they’re not, they’re irritated by it, and changing to the ointment sorts out the problem.”
Other types of dermatitis
“Older people with varicose veins can get stasis dermatitis, which is due to poor circulation,” says Dr Mayou. Because poor blood flow usually develops in the lower legs, stasis dermatitis – also known as venous or varicose eczema – appears on the lower legs and ankles. Emollients and topical corticosteroids are frequently used to reduce inflammation and itching in acute flares.
Asteatotic eczema is a common type of dermatitis that occurs as a result of dry skin. While it can occur in anyone with very dry skin, it most often affects older people, and certain drugs such as diuretics can trigger it.
Dyshidrotic eczema, a type of skin inflammation that causes a burning, itchy rash or blisters, affects your palms, the sides of your fingers and the soles of your feet. In some people, symptoms can be quite severe. It can be an allergic response to exposure to certain substances, including cement and nickel. Other allergies, including hay fever or food allergies, may also cause flares, as can frequently sweaty or wet hands or feet. Moisturiser plays a key role in helping your skin heal, as does washing with lukewarm water and mild, fragrance-free cleansers.
Dermatitis on the scalp
Dermatitis on the scalp is also known as dandruff, and it’s estimated that seborrheic dermatitis and dandruff combined affect half of the adult population. “Typically, with seborrheic dermatitis the only symptom is dandruff, but you can sometimes also get inflammation on the scalp. Some people can also get bumps, widespread redness or scaling and itching,” says Dr Laftah. “If it goes on for long enough you can also get hair loss due to the inflammation around the hair follicle. But this grows back once you use a product or shampoo specifically for dermatitis of the scalp.”
Dermatitis on the face
When dermatitis appears on the face it can be perioral dermatitis, with tiny red bumps that form on the lower half of the face, in the folds of the nose and around the mouth. “Typically, in such cases we have to try to optimise the barrier function and remove any irritant products like, for example, retinoids, and then if the barrier function’s improved but the inflammation persists, we tend to use acne medication to clear it,” says Dr Laftah.
Alternatively, facial flare-ups can be seborrheic dermatitis, where excess oil exacerbates the condition. “In this case I tend to advise using a gentle foaming cleanser to reduce some of the oil build-up. This approach wouldn’t be suitable for perioral dermatitis or eczema as some foaming cleansers can dry the skin – a cream cleanser would be better,” says Dr Laftah.
“If we can’t work out why a patient is getting facial eczema, we will investigate with a patch test to identify their allergens,” says Dr Mayou. “We can even identify chemical compounds in products and perfumes that are a trigger and work out, for example, that a patient is safe to wear Chanel No 5 but not Miss Dior.”
On the whole, treatment for facial dermatitis involves avoiding further irritation from triggers, plus gentle cleansing and treatment with medical products. Mild facial eczema can sometimes be treated with consistent moisturising. If recommended by your doctor or dermatologist, one per cent hydrocortisone creams can be used for a short time only, as they pose less risk of skin thinning. Otherwise, topical calcineurin inhibitors or TCIs, non-steroidal medications that block chemicals that can make your eczema flare-up, are sometimes prescribed, as these creams and ointments do not lead to skin thinning, especially around the eyes and on the eyelids.
Is it safe to use hydrocortisone cream?
Some people are wary of taking steroids for their dermatitis, due to potential side effects like permanent thinning of the skin, but the risk is very small if the correct strength is used properly in the correct quantity. This is why it’s important for patients to get advice from a dermatologist, says Dr Mayou. “A dermatologist will prescribe the lowest possible strength that’s appropriate to them.”
Topical steroids come in the form of an ointment or cream. “We tend to give ointment for dry conditions and creams for wet [i.e. weeping] ones,” says Dr Mayou. You can buy one per cent cream over the counter, or Eumovate, which is a stronger steroid cream. “This means patients can go on buying their own products without a prescription, as long as they know what’s the appropriate strength for them, which means an initial consultation with a dermatologist,” says Dr Mayou. And don’t stop using it as soon as your skin looks better. “You need to continue until you’ve got histological [at a deep cellular level] as well as clinical cure. The acute inflammation cells in the skin will quickly melt away with a steroid and you will look and feel better, but you need to continue for longer to get rid of the chronic inflammatory cells,” says Dr Mayou.
How long does dermatitis last?
With contact dermatitis, the rash can develop within minutes to hours of exposure, and it can last two to four weeks, until the skin heals. More severe or persistent cases may last for a few weeks or even months, and if you have had many exposures to an allergen over time, it may take three to six months for your skin to get completely better after you start avoiding it.
While atopic dermatitis flares can last a long time, you can control them by avoiding irritants, using appropriate treatments and keeping your skin well-moisturised. Perioral dermatitis requires several months of treatment, without which it may be permanent. Seborrheic dermatitis is also a chronic condition that requires management when flares occur.
Which cleansers should you use?
And if you’re prone to dermatitis, get used to using soapless cleansers, such as Dermol 500, as well as moisturisers. “There’s a spectrum of moisturisers, from lotions and creams to ointments, depending on how bad your dermatitis is. I often recommend Cetraben and CeraVe,” says Dr Mayou.
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