Eczema

Eczema is a group of conditions in which the skin barrier works poorly and the skin becomes inflamed: dry, itchy, red or darkened, sometimes cracked, weeping or thickened. The commonest form by a wide margin is atopic eczema, which usually begins in early childhood and runs in families alongside asthma and hay fever. This article is mainly about that one.

It cannot be cured. It can almost always be controlled, and most children who have it see it improve substantially as they grow. The gap between a well-managed case and a badly managed one is enormous, and it is largely a matter of two unglamorous things being used properly and in sufficient quantity.

It is worth saying at the outset what the two things are, because a great deal of writing on eczema talks around them. They are emollients and topical corticosteroids. Nearly everything else is secondary.

Emollients, and why quantity is the point

An emollient is a moisturiser used as a medicine rather than a cosmetic. It replaces the fats the barrier is missing, holds water in the skin and reduces itch, and it is used on the whole body every day — including when the skin looks clear, because the barrier is still faulty between flares.

The commonest mistake is using far too little. UK guidance for a child with atopic eczema is to prescribe 250 to 500 grams a week of leave-on emollient, which is a quantity that surprises most people the first time they hear it, and enough that supplies need to exist at nursery or school as well as at home. An adult with widespread eczema uses more.

How it is used matters too:

• Smoothed on in the direction of hair growth, not rubbed in. Rubbing irritates inflamed skin and can block follicles.
• As a soap substitute. Soap, shower gel, bubble bath and detergent-based washes strip the barrier and are among the most reliable triggers there are. An emollient used in place of them removes the problem rather than treating it.
• Hair washed outside the bath water, with an unperfumed shampoo, so that the rest of the body is not sitting in it.
• Several minutes between products. Where an emollient and a steroid are both being applied, they go on one at a time with a gap, not mixed together.
• Taken from the tub with a clean spoon rather than fingers, which keeps a pot of emollient from becoming a culture of whatever is on the hand.

Two corrections to advice that circulates widely. Emollient bath additives do not help — they were tested in a large UK trial and NICE guidance is now not to offer them; a leave-on emollient can be added to the water instead, or simply applied after. And drinking more water does not moisturise skin. Dehydration is bad for a person generally, but an eczema flare is a barrier and inflammation problem, not a fluid-intake problem, and the eight-glasses figure has no particular basis.

On kitchen oils: olive oil is often recommended and UK research has found that applying it to infant skin measurably reduces barrier integrity, which is the opposite of what an emollient is for. Advice has moved away from it. Coconut oil suits some people and sensitises others. Neither has any advantage over an emollient prescribed for the purpose.

One safety point that belongs with emollients and is not widely known. Emollients are a fire risk. They soak into clothing, bedding and bandages, and the fabric then catches light far more readily and burns fiercely. This applies to paraffin-based products and, following a UK review, to paraffin-free ones as well. Anyone using them regularly should keep away from naked flames, cigarettes and open fires, and wash fabrics at a high temperature — though washing does not remove the risk entirely.

Steroid creams, and the fear of them

Topical corticosteroids are the treatment that settles a flare. They are also the single most under-used treatment in eczema, because a great many people have absorbed the idea that they are dangerous and should be avoided or used in the smallest possible dab.

A claim that circulates widely — that prescribed eczema treatments are irritating, often make the condition worse, and frequently do not work at all — is a fair example of how that belief gets reinforced. It is not an accurate description of topical corticosteroids used correctly.

Used correctly means matched to severity and to the part of the body:

• Potency follows severity — mild for mild eczema, moderate for moderate, potent for severe.
• Face and neck: mild potency. A moderate one may be used there for three to five days in a severe flare, but not as a routine.
• Armpits and groin: short courses only, seven to fourteen days, since skin there absorbs more.
• Once or twice daily, not more. More often does not work better.
• Only on skin that is actively affected, or was within the last couple of days — not spread over clear skin as a precaution.
• Continued for about forty-eight hours after the flare settles, rather than stopped the moment it looks better, which is the usual reason a flare returns within days.

The fingertip unit is the standard measure: the amount squeezed from a tube along the end segment of an adult index finger, which covers an area about twice the size of a flat adult hand. It is a practical way of applying enough, which is the more common error in the other direction.

Where flares come every few weeks, there is good evidence for treating the usual trouble spots on two consecutive days each week once things are under control, rather than waiting for the next flare and chasing it.

It is also worth labelling the tube itself with its potency class. Potencies are not obvious from the name, several look alike, and the label is usually on the box that gets thrown away.

Topical steroid withdrawal

Some people who have used topical steroids for long periods, usually potent ones on the face or in large amounts, describe a reaction when they stop: burning and intense redness spreading beyond the areas that were treated, which can take months to settle. This is referred to as topical steroid withdrawal.

The position taken jointly by British dermatologists and the National Eczema Society is a fair summary of where the evidence stands. The reaction is acknowledged and properly researching it is overdue; it is also poorly defined, and some of what gets attributed to it is either a recognised steroid side effect or a different condition altogether. Their practical conclusion is the one that matters here: concern about it should not put people off using topical steroids where those help, because undertreated eczema causes a great deal of avoidable suffering of its own.

Anyone worried about how much they have been using, or wanting to come off a long course, is better served by asking for advice than by stopping abruptly. Alternatives exist. Stopping without a plan is what produces the worst rebounds.

Persistent facial redness that a mild steroid does not help, or that improves and then returns worse each time, is worth having reassessed rather than treated harder — facial redness is sometimes rosacea, which steroid creams make considerably worse.

Diet, which is where real harm gets done

Food is the first place most people look, and the advice in circulation — cut out dairy, eat raw rather than cooked, avoid processed food, consider that toxins from food are causing the outbreak — is a mixture of the unproven and the actively risky.

What is true: food allergy genuinely does play a part in a minority of cases, mostly babies and young children with moderate or severe eczema that good topical treatment is not controlling, and particularly where there are gut symptoms or poor weight gain. Where that is the picture it is worth investigating properly.

What is not true is that this applies to most eczema, and the consequences of assuming it does are serious:

• Children on long-term exclusion diets without dietetic supervision can fall off their growth curve. A cow's-milk-free diet followed for more than about eight weeks is a reason for specialist dietary advice, not something to keep running indefinitely.
• Removing a food a child was previously eating without reaction can cause a genuine allergy to develop to it — so that a food which was merely suspected becomes a food that provokes a reaction on reintroduction. This is the opposite of the intended outcome and it is not rare.
• Allergy tests bought on the high street or online — hair analysis, kinesiology, IgG food-intolerance panels — do not identify food allergy, and UK guidance advises against them. They produce long lists of foods to avoid, which is how most unnecessary exclusion diets begin.
• Goat's and sheep's milk are not substitutes for cow's milk where allergy is suspected, since the proteins are similar enough to cross-react.

Keeping a brief diary of flares is harmless and occasionally revealing. Acting on it by removing foods, especially from a child's diet, is a decision to take with a dietitian rather than alone.

Other triggers worth knowing about

Soap and detergent are the big ones, and that includes shower gel, bubble bath, washing-up liquid and biological laundry products. Heat and sweat, sudden temperature change, wool and other rough fabrics next to the skin, and dry indoor air in winter all provoke flares. Stress reliably makes eczema worse, which is not the same as stress causing it.

House dust mite is a genuine allergen for many people with atopic eczema, but the elaborate mite-reduction measures sometimes recommended — barrier bedding, removing carpets, special vacuuming regimes — have not been shown to improve eczema enough to justify the effort and expense, and are not routinely advised.

A note on contact dermatitis, which is a different sort of eczema: where a rash is confined to one area with a sharp edge — around a watch strap, on the earlobes, on the hands, under a waistband — an allergy to something touching the skin is likely, and patch testing identifies it. Nickel, fragrance and preservatives in cosmetics are the usual culprits. Fragrance allergy is worth bearing in mind by anyone treating their skin with essential oils, since the declarable fragrance allergens on cosmetic labels are largely constituents of those oils.

Infection, and the one thing that is an emergency

Eczema-affected skin is readily colonised and infected by bacteria. The signs that an infection has set in are weeping, yellow crusting, pus-filled spots, a flare that is spreading unusually fast, eczema that has stopped responding to treatment that was working, and feeling unwell or feverish. That needs seeing and usually needs antibiotics. Afterwards it is worth replacing tubes and tubs of topical medication, which become contaminated.

The emergency is different and needs recognising on sight. Eczema herpeticum is the cold sore virus spreading across eczema-affected skin. It presents as rapidly worsening, unusually painful eczema with clustered blisters that look like early cold sores, and small round punched-out sores a few millimetres across, often with fever, lethargy and a child who is clearly unwell.

This requires same-day medical assessment, not an appointment next week. It is treated with antiviral medication, and when it involves the skin around the eyes it needs an eye specialist the same day as well. It is the one complication of eczema that can become dangerous quickly, and it is absent from most older writing on the subject.

When topical treatment is not enough

Where eczema remains severe despite emollients and steroids used properly, there is more available. Tacrolimus and pimecrolimus ointments are non-steroid anti-inflammatories used as a second line, particularly on the face. Ultraviolet light treatment is given in hospital dermatology departments. For severe eczema in adults and older children, a group of newer injected and oral drugs — biologic treatments and targeted tablets — has changed what is achievable, and access to them is through a dermatologist.

Antihistamines, by contrast, do less than their popularity suggests: current guidance is not to use them routinely for eczema, though a short course of a sedating one can help a child whose sleep is badly disrupted during a flare.

When to be seen

Same day for suspected eczema herpeticum — painful, rapidly spreading eczema with clustered blisters or punched-out sores, especially with fever.

Within a week or two where severe eczema has not responded to proper topical treatment, or where a treated skin infection has not cleared.

Routinely where the diagnosis is uncertain, where flares take up one or two weeks of every month, where facial eczema is not responding, where contact allergy is suspected, where several emollients have caused reactions, or where sleep, school or work is being affected. That last one is a legitimate reason on its own and is consistently under-reported.

And for a child whose growth has fallen away from its expected curve, particularly on any kind of exclusion diet, that should be raised promptly.