Treatment of atopic dermatitis

Is there a cure for atopic dermatitis?

There is no known cure for atopic dermatitis (eczema). As a large part of the tendency towards eczema is genetic, there is unlikely to be a cure anytime in the foreseeable future. There is, however, ongoing research and very effective treatments.

Several treatments are available that will control the eczema so the skin looks and feels normal.

• The treatment chosen by the patient and doctor depends on the pattern, severity and duration of eczema.
• The trigger factors for eczema should be avoided as much as possible. This does not involve an exhaustive search for allergies as these only play a small role in most people.
• In general topical treatments are used first as they are effective for most patients if used correctly and have the fewest side effects.
• If the eczema has failed to respond to topical treatments or is too severe for topical treatment alone, ultraviolet light (phototherapy) may be helpful. Phototherapy is not suitable for everyone due to practical difficulties (such as travel or immobility) or photosensitivity.
• Oral medications may be offered to those with severe or treatment-resistant eczema. Although these are usually effective, they have side effects and risks that make them unsuitable as first line treatment.

Topical treatments for atopic dermatitis

Most people with eczema use topical treatments (lotions, creams and ointments). When the surface of skin is inflamed, cracked or raw, many of these sting or burn when first applied. This irritation will lessen as the eczema improves. It is worth persevering for at least a few days. If the stinging persists beyond this or causes welts or the eczema gets worse, stop the treatment and consult your doctor.

Emollients

Emollients provide moisture to the skin and help prevent further water loss. They should be used in almost everyone with eczema in an attempt to restore skin barrier function. Emollients are a very important part of eczema management, even (especially) when the eczema is well controlled. Remove the emollient from the pot using a clean spoon to avoid contamination. Note: clothing soaked in paraffin-based emollients becomes a fire hazard.

• Dry skin almost always accompanies atopic dermatitis. Correcting it can lessen stinging and itching, reduce the number of flares and infections, and improve the appearance.
• Creams are most commonly used. Lotions are easy to apply but evaporate quickly and may not be oily enough. Ointments are more effective than creams in very dry skin but are unappealing because they are hard to rub in and leave a greasy surface. Ointments can also encourage folliculitis and boils by blocking the hair follicles. Finding the right emollient may be a case of trial and error.
• Expensive, cosmetic emollients are rarely any better than cheap ones. They often contain perfumes or other additives that irritate the skin.
• Emollients should be used at least twice a day all over the skin. They are best applied within three minutes after a shower or bath to maximise their moisture-retaining effect.
• In New Zealand (2014), PHARMAC subsidises urea cream (very good for dryness but can sting active eczema); 3% wool fat with mineral oil lotion; cetomacrogol (nonionic cream); oil in water emulsion (fatty cream); and cetomacrogol with 10% glycerol.
• Aqueous cream and emulsifying ointment are also funded by PHARMAC. These are best used in place of soap or detergent for cleansing dry skin. Rub on to the skin and rinse off. If these prove unsuitable, there are several other suitable unfragranced non-soap cleansers.
• Bath additives may include (unfunded) colloidal oatmeal, and bath oils (these make bath surfaces slippery). Note that a trial published in 2018 found no evidence of clinical benefit from including emollient bath additives in the standard management of eczema in children. 
• FDA-approved products composed of ceramides, cholesterol and fatty acids aim to mimic the lipids naturally found in the horny layer of the skin and may reduce the need for anti-inflammatory medications.

Topical steroids

Topical steroids are the mainstay of treatment for mild to moderate eczema. They are also used in severe atopic dermatitis to reduce the dose of oral treatments and ultraviolet light. They are very effective and safe if used correctly. Despite this, many people are concerned about potential side effects from topical steroids. The trick is to use the correct strength of steroid for the severity of the eczema and be prepared to change treatment as the severity of the eczema changes.

• The thickness of skin varies in different areas of the body. The thinnest skin is found on the face (particularly the eyelids), genitals, body folds and the skin of infants. These areas absorb topical steroids very readily and are more prone to local side effects from them.
• Systemic absorption and adrenal suppression is only a concern if large amounts of potent topical steroids (e.g. more than 100g/week) are used over a long period of time (months).
• Topical steroids can further reduce the skin barrier function so are best applied as intermittent courses so it can recover.
• In general, the lowest strength and smallest quantity of topical steroid that is effective should be used, applied to all areas affected. There is no benefit from applying them more than once daily; use an emollient if the skin is dry or irritable.
• Mild eczema is likely to respond to low potency topical steroids within a few days, often with complete clearance of eczema within one or two weeks. Moderate eczema may require more potent topical steroids for at least two weeks before improving and may require several weeks of treatment before clearing. Severe eczema may show only partial improvement with potent topical steroids alone even after several months of use.
• It is important to use the treatment as directed for best results and to avoid side effects. One of the most common reasons topical steroids are ineffective is that they are not used enough.

As eczema tends to be persistent, most people will have to use topical steroids on and off for many years. If used continuously topical steroids may lose their effectiveness after a few weeks (this is known as tachyphylaxis). Tachyphylaxis can be avoided by reducing the strength and frequency of the topical steroid as the eczema comes under control.

• Intermittent treatment works very well for mild eczema, which responds within a week or two to relatively weak topical steroids and can often be maintained with emollients alone. If it flares, the same topical steroid can be used again with good effect.
• Moderate and severe eczema are more difficult to manage. The eczema may not have completely cleared with a potent topical steroid after three to four weeks. This can be managed by gradually reducing the number of days the stronger topical steroid is used, for example using a potent topical steroid at weekends and an emollient on weekdays.
• If tachyphylaxis occurs, treatment needs to be tailored to the individual patient. Changing to a different topical steroid of the same strength can be helpful. Treatment of infection, if present, may again make the topical steroid effective. A stronger topical steroid or an additional treatment such as phototherapy may be required.

Topical immunomodulators

The topical immunomodulators or calcineurin inhibitors pimecrolimus cream (Elidel™) and tacrolimus ointment (Protopic™, which is not yet available in New Zealand) are particularly useful for mild to moderate atopic dermatitis. They are antiinflammatory but do not thin the skin or affect its barrier function.

• Topical pimecrolimus is most effective when used at the earliest sign of eczema (such as redness or itching) to prevent flares.
• Topical tacrolimus is more potent and may have greater immunosuppressive activity.
• Short courses of topical steroids are more suitable for flares.
• The main side effect is initial burning, feeling of warmth or itching.
• Topical immunomodulators are particularly useful for eczema in thin-skinned areas (face, genitals and body folds).

Crisaborole (Eucrisa®) is a novel non-steroidal topical anti-inflammatory PDE-4 inhibitor reducing the production of inflammatory cytokines used for the treatment of mild to moderate atopic dermatitis. The FDA approved the drug in December 2016.

Antiseptic solutions

Antiseptic solutions can also be helpful in infected eczema as long as the concentration is not too high or they can have an irritant effect on the skin. Apply an emollient as well.

• Bleach bath: add half a cup of household bleach (6% sodium hypochlorite solution) to a full bath and soak for 10 minutes.
• Condy's crystals (potassium permanganate) are used in weak concentration in the bath (just enough to make the water a light rose pink colour).
• Other antiseptics include cetrimide, chlorhexidine, chloroxylenol, dibromopropamidine, polynoxylin, povidone iodine and triclosan.

Tar preparations

Coal tar, pine tar and ichthammol preparations are available as creams, bandages and bath additives. Although reducing itch and inflammation, they can be smelly and messy and do not appear as effective as topical steroids.

Wet wraps

‘Wet wraps’ are wet bandages applied over emollients +/- topical steroids. Tubular elastic bandages are convenient. Wet wraps are used in acute red, hot, weeping eczema and usually require admission to hospital. They can quite quickly gain control of eczema and appear to work by cooling and moisturising the skin. They also protect the skin from damage due to scratching. They can be repeated for several days or longer, reapplied as they dry out.

Antibiotics in the treatment of atopic dermatitis

• Antibiotics are sometimes very important in the management of atopic dermatitis, most often when there are signs of bacterial infection such as weeping, crusting, pustules or painful swelling (cellulitis). The antibiotics are mostly given orally, but sometimes hospital admission is necessary for intravenous treatment.
• In New Zealand, the penicillin derivatives flucloxacillin or dicloxacillin are usually prescribed, or erythromycin in those allergic to penicillin. Another drug active against staphylococcus and streptococcus may be preferred.
• On discontinuing the oral antibiotic, the patient may suffer another flare. If this occurs repeatedly, antibiotics may be prescribed for several weeks or months. There is a low risk of side effects from such treatment. The main concern is the development of bacterial resistance to antibiotics (MRSA).
• Antibiotic creams and ointments are not recommended for use in extenisve atopic dermatitis. They are not as effective as oral antibiotics. They may also cause contact allergic dermatitis or promote the development of bacterial resistance to antibiotics.

Oral antihistamines in the treatment of atopic dermatitis

• Antihistamines are sometimes helpful in the management of patients with atopic dermatitis, especially if the patient also has dermographism or other forms of urticaria.
• A trial of a non-sedating antihistamine such as cetirizine for several months is often recommended, and in other cases sedating antihistamines may be prescribed short-term to reduce insomnia due to scratching.
• However, there is no high-level evidence to support the effectiveness of antihistamines in the management of pruritus associated with atopic dermatitis.

Phototherapy for atopic dermatitis

• Phototherapy or ultraviolet (UV) treatment is reserved for severe eczema as it is expensive, time-consuming and has potential side effects. It involves controlled exposure to UV-B and/or UV-A for a few minutes two to three times each week. A treatment course may continue for several months.
• More severe cases may require photochemotherapy (PUVA) or, where available, UVA1.
• Topical treatments are usually continued. Additional emollients may be necessary as phototherapy may aggravate dryness.
• Phototherapy is unsuitable for those who have little flexibility with work or school hours, mobility or transport problems, very fair skin or a history of photosensitivivity. It is also unsuitable for very young children as they are unable to stand still for the required period of time and cannot be relied upon to wear safety glasses.

Systemic treatments for atopic dermatitis

The following oral medications are reserved for severe eczema, usually after a trial of phototherapy has at least been considered.

• The oral corticosteroids prednisone and prednisolone are often used in the short-term management of severe eczema. Oral corticosteroids gain rapid control of the eczema but they cannot be continued for more than a few weeks at a time without significant side effects.
• If an ongoing oral medication is required a non-steroidal immunosuppressant agent such as azathioprine, methotrexate, ciclosporin or mycophenolate may be used to enable the dose of steroid to be reduced and eventually discontinued.

Despite the potential long-term side effects of immunosuppressive agents, most patients who take them for severe eczema are very happy with the result as it frees them from otherwise disabling eczema. Immunosuppressant agents are not intended for indefinite use but if severe eczema relapses every time they are stopped they may be needed at least intermittently for many years.

Biologic medications are being developed for atopic dermatitis. A monoclonal antibody that targets Th2 cytokines interleukin (IL)-4 and IL-13 (responsible for reduced barrier function and inflammation), Dupilumab (Dupixent®), was approved by the for the treatment of atopic dermatitis in March 2017. The results of Phase 2 trials for nemolizumab have been reported.

Behavioural therapy for atopic dermatitis

Scratching damages the skin, aggravating the eczema, which then itches even more. Some scratching is just a bad habit or stress reaction. Behavioural therapy can be helpful to develop strategies to reduce scratching (habit reversal) thus leading to improvement in the eczema.

Unproven therapies used in atopic dermatitis

So-called cures for atopic dermatitis abound, with many examples found readily on the Internet. Most are ineffective. Some are potentially hazardous. Insufficient evidence exists to recommend probiotics, leukotriene inhibitors, essential fatty acids or traditional Chinese medicines. Allergen immunotherapy may be useful in a small number of individuals with proven sensitisation to inhalant allergens.

Future treatments for atopic dermatitis

• Tofacitinib is a Janus kinase inhibitor under investigation orally and topically for atopic dermatitis. Clinical trials are in Phase II.
• Many other drugs are being evaluated in clinical trials for the treatment of atopic dermatitis.