Topical therapy: emollients and corticosteroids

• Dry skin and inflammation sit at the root of most common rashes (eczema, psoriasis, dermatitis). Fixing both arms - repair the barrier and quieten the inflammation - is what makes topical treatment work.
• Emollients are the foundation: used every day, on all skin, in generous quantities, even when the skin looks clear. They are a treatment, not a cosmetic.^[3][4]
• Topical corticosteroids (TCS) are the first-line anti-inflammatory. Match potency to the condition, the body site and the patient's age; once-daily application is generally as effective as twice daily.^[4]
• Underuse is the commonest reason treatment fails. A fingertip unit (FTU) - the cream squeezed from fingertip to first finger crease - covers roughly the area of two adult hands.^[2][4]
• Always leave a gap between emollient and steroid (about 20 to 30 minutes) and a longer gap before a calcineurin inhibitor (about 2 hours).^[3][4]
• Emollients soak into fabrics and make them more flammable, even after washing. Patients must keep away from naked flames and cigarettes.^[6]
• Topical calcineurin inhibitors (TCI) are steroid-sparing, do not thin skin, and suit the face, eyelids, flexures and genitals.^[4][5]
• Refer when control is not achieved with optimal topical therapy, when the diagnosis is uncertain, when very potent steroids are needed on delicate sites, or when topical steroid withdrawal is possible.^[1][2]

By the end of this page you should be able to:

1. Explain why emollients are the foundation of topical therapy and how to choose, prescribe and apply them, including the fire risk with fabric.
2. State the four UK potency groups and the five US potency classes, and match potency to body site and age.
3. Measure topical corticosteroid dose with fingertip units and plan a sensible quantity to prescribe.
4. Anticipate and monitor the local and systemic adverse effects of topical corticosteroids, including topical steroid withdrawal.
5. Use topical calcineurin inhibitors as steroid-sparing agents and apply wet wraps safely.
6. Decide when to refer a patient for specialist dermatology input.

This page is about how to use these agents well, whatever the underlying skin disease. It is written from the same principle as the atopic dermatitis page: emollients at every step, anti-inflammatories only where and when needed, and quantity and potency chosen with care.

Topical therapy is prescribed more than any other drug class in dermatology, and it is also the drug class most often used badly. ^[4] Under-prescribing, under-use by patients and steroid phobia on one side, and over-potent steroids on thin skin on the other, both cause real harm. ^[2] The aim is the middle ground: enough emollient, the right steroid at the right site, in the right amount, for the right length of time.

Emollients soothe and soften dry skin and help it hold moisture. They protect the outer layer of the skin and reduce water loss. They are not a cure, but in eczema they reduce flares, reduce the need for steroid, and make other topical treatments work better. ^[3] They should be used every day, even when the skin looks normal, and on all skin rather than only on the dry or inflamed patches. ^[1][3]

Emollients come as ointments, gels, creams, sprays and lotions. ^[3]

• Ointments are the greasiest (oil-based). They are best for very dry, lichenified or scaly skin and have the strongest moisturising effect.
• Creams are an oil-and-water mixture, less greasy, and widely used day to day.
• Gels rub in easily and may contain added moisturising ingredients.
• Sprays help where the skin is sore, infected or hard to reach.
• Lotions contain more water, are easier to spread, and suit the scalp and hairy areas.

There is no single best emollient. The best one is the one the person will actually use, applied smoothly in the direction of hair growth to avoid folliculitis. ^[3] Many people prefer a lighter preparation by day and a greasier one at night. Creams and lotions are often preferred in warm weather; ointments when the skin is very dry.

A few practical points matter. Emollients containing sodium lauryl sulphate (SLS) are not recommended because SLS can irritate and inflame the skin. ^[3] Preservatives in emollients can also sting sore skin or cause a rash, so if a tub consistently stings, try a different product. ^[3] Tub containers should never have fingers dipped into them: use a clean spoon each time. ^[3] Bath oil (emollient bath additives) are not routinely offered. ^[1]

Emollients are under-prescribed. UK guidance suggests an adult with a dry skin condition (such as atopic dermatitis or psoriasis) typically needs about 500 g of emollient per week, and a child 250 g to 500 g per week. ^[4] Quantities should be generous and written on the repeat prescription, including smaller packs for school or work bags.

Application frequency varies with dryness: from using an emollient soap substitute once or twice a day, to several applications daily when the skin is severe. It would be unusual to need more than three applications a day if the underlying inflammation is also being treated. ^[3]

Emollients should not be applied at the same time as TCS or TCI, because they can dilute the drug and reduce its effect. ^[4] Two safe rules of thumb exist: leave about 30 minutes between an emollient and a TCS, and about 2 hours between an emollient and a TCI. ^[3][4] NICE states that individual preference should decide which product is applied first. ^[1] When both are used, some experts advise a gap of at least 20 to 30 minutes either way. ^[1][3]

This is the single most important safety message about emollients. All emollients - not just paraffin-containing ones, but paraffin-free ones too - soak into clothing, bedding, bandages and dressings and dry there. Once dried into fabric they make it more flammable, and the resulting fire burns quickly and intensely, causing serious injury or death. ^[6] The risk remains even after washing; washing at high temperature reduces the build-up but does not remove it completely. ^[6]

Every patient (and their carers) must be told:

• Do not smoke, use naked flames (including gas hobs and candles) or get near anything that could ignite a fire while wearing clothing or bandages that have been in contact with emollient. ^[6]
• Change and wash clothing and bedding frequently to reduce build-up, but do not assume washing removes the risk. ^[6]
• Keep emollient off the fabric of furniture, cushions and blankets. ^[6]
• Tell relatives and carers about the treatment so they can help reduce the risk. ^[6]
• Tell the prescriber if the person smokes, so that help to stop can be offered. ^[6]

The BAD patient leaflets carry an identical caution and refer patients to the MHRA guidance for full detail. ^[2][3][6]

TCS are grouped by potency. In the UK the groups are usually described as mild, moderate, potent and very potent (super potent). ^[1][2] Commonly used preparations in each group include: ^[4]

In the US TCS are classified into seven classes, from class I (highest potency) to class VII (lowest). ^[4]

The general rule is to match potency to the affected site and to the severity of the disease: lower potency on thin skin (face, eyelids, neck, flexures, genitals) and higher potency on thick skin (palms, soles, trunk, limbs, scalp). ^[4][5] Body site matters more than the diagnosis: regional skin permeability varies more than 400-fold, so a single potency applied everywhere will atrophy thin skin and be futile on thick skin. ^[4] Sensitive sites (face, flexures, groin) are more prone to side effects. ^[2]

Practical rules from the UK and US guidance: ^[1][2][5]

• In adults, a potent steroid may be used on trunk and limbs and a mild or moderate one on the face and flexures; moderate steroids should be used on the face for the shortest time needed.
• In children, a moderate steroid may be used on trunk and limbs and a mild one on the face and flexures. Potent steroids are not used in children under 12 months without specialist advice, and very potent steroids not in children of any age without specialist advice. ^[1]
• Very potent steroids are usually prescribed only by specialists. ^[1]
• Hyperkeratotic or lichenified conditions (such as lichen simplex, nodular prurigo, palmoplantar psoriasis) can warrant more potent steroids than the site alone would suggest. ^[4]
• For severe eczema, consider a high- or very-high-potency steroid (class I to II) to control the flare, then step down. ^[5]
• TCS are strong treatments and first-line for mild to severe disease, but over large areas the risk of systemic absorption rises. ^[4][5]

The NICE CKS groups available steroids into the four potencies (mildly potent, moderately potent, potent, very potent), gives example preparations, and tailors strength to severity and site, with the same age limits. ^[1]

AAD guidance for adults adds two useful frequency points: use lower-potency agents on the face, neck, genitals and body folds, and apply a medium-potency steroid twice weekly between flares to reduce relapse. ^[5]

Under-treatment is one of the commonest reasons TCS therapy fails: patients told to "apply sparingly" use too little. ^[2][4] The fingertip unit solves this. One FTU is the amount of cream or ointment squeezed from a standard tube (5 mm nozzle) from the tip of the adult index finger to the first crease. It is enough to cover an area about the size of two adult hands with the fingers together. ^[2][4] Prescribing by FTU makes the dose concrete. ^[1]

For children the FTU is still measured with an adult finger, but fewer units are needed at each age; the rough adult guide is not used unchanged. ^[1][4]

Evidence suggests that applying a TCS once daily is generally as effective as twice daily for treating dermatitis flares, and a once-daily regimen is simpler. ^[4] The older advice "twice daily by default" is therefore being revised. ^[4] AAD recommends applying a medium-potency steroid twice weekly between flares to prevent relapse. ^[5]

Potent and very potent steroids should be prescribed for limited periods only, with moderate potencies used for maintenance if needed. ^[4] For eczema flares, NICE advises matching strength to severity and using it once daily for a short defined course, stepping up or down by severity and site. ^[1] Exact day counts published by NICE (for example 7 to 14 days for a flare) and by other sources differ between guidelines; follow the most current local guideline for the condition and the patient, and review rather than repeat indefinitely. ^[1][4]

Vehicle also matters: ointments are more occlusive and penetrate better, suiting dry, thickened or scaly skin; creams and lotions suit weeping or hairy areas; foams, shampoos and solutions suit the scalp. ^[4] Apply TCS in the direction of hair growth to reduce folliculitis. ^[2] Waiting about 20 to 30 minutes after an emollient before applying the TCS avoids diluting it. ^[1][3]

TCS are effective and safe when used correctly; the benefit outweighs the harm. ^[1][2] Most problems come from prolonged or over-potent use on thin or large areas of skin. ^[4][5]

• Skin thinning (atrophy) - usually improves after stopping. ^[4]
• Telangiectasia, purpura, bruising. ^[4]
• Striae (stretch marks) - may be permanent. ^[4]
• Acne or worsening acne, rosacea, perioral dermatitis. ^[2][4]
• Folliculitis. ^[2]
• Mild, usually reversible depigmentation. ^[2]
• Hypertrichosis (excess hair growth at the treated site). ^[2]
• Worsening or spreading of untreated infection. ^[2]
• Transient burning or stinging in the first days, which usually settles. ^[2]
• Allergic contact dermatitis to the steroid or the excipients. ^[2]
• Periocular use may be linked to cataracts or glaucoma - minimise use around the eyes. ^[5]
• Spread and severity of untreated skin infection. ^[2]

These are more likely with potent or very potent preparations used continuously over large areas (more than 10% of body surface area), on thin or inflamed skin, under occlusion, and in children or older adults. ^[4][5]

• Growth suppression in children. ^[4][5]
• Adrenal (HPA axis) suppression, sometimes confirmed with a cortisol stimulation test. ^[4][5]
• Cushing's syndrome. ^[4]

AAD adds a possible but not yet established association between TCS use and type 2 diabetes and osteoporosis. ^[5]

TSWS is a recognised but uncommon adverse effect of prolonged TCS use, and a controversial and poorly defined one, because the evidence base is thin. ^[2][4] Reported cases most commonly involve prolonged (at least 6 to 12 months in adults) and frequent use of moderate- or high-potency steroids, especially on the face, neck, genitalia and flexures. ^[2][4] It presents as redness that extends beyond the area originally treated, with burning or stinging that is worse than the original condition. ^[2][4] Characteristic features include burning or stinging pain out of proportion to itch, diffuse erythema, oedema, and symptoms starting shortly after the steroid is withdrawn. ^[4] Recognised (but not validated or always present) signs include the "elephant skin" sign (oedematous folds), the "red sleeve" sign (limb erythema with a sharp cutoff at palm or sole), skin flaking ("snow"), and facial erythema sparing the nasal and perioral area ("headlight sign"). ^[4] There is no diagnostic test; it is a diagnosis of exclusion and must be distinguished from severe uncontrolled dermatitis, allergic contact dermatitis and erythroderma. ^[4]

The practical lesson is that TSWS is driven by the very pattern most to be avoided: prolonged unsupervised potent steroid on delicate skin. ^[2][4][5] MHRA patient safety material on TSWS exists and the BAD and NICE-adjacent guidance list it among reasons to refer. ^[4]

• Use the least potent preparation that controls the disease, and step up or down. ^[1][2]
• Reserve very potent steroids for brief periods and specialist oversight. ^[1][2]
• Do not use TCS on broken skin or untreated infection (impetigo, cold sores, fungal infection) unless combined with an appropriate anti-infective under advice, and avoid them in acne, rosacea and perioral dermatitis. ^[2]
• Undershooting (using less than advised, or stopping too early) makes the disease harder to control and pushes the patient onto stronger preparations. ^[2]
• TCS are safe in pregnancy and breastfeeding and have no age limit, though the potency limits above still apply. ^[2]

Tacrolimus (ointment 0.03% and 0.1%) and pimecrolimus (cream 1%) are TCI: non-steroidal anti-inflammatories that block calcineurin in T cells. ^[4][5]

• They do not cause skin atrophy, so they suit the face, eyelids, flexures and genitals particularly well. ^[4][5]
• They are licensed for atopic dermatitis and widely used off label in other inflammatory dermatoses. ^[4]
• Tacrolimus 0.1% ointment is more effective than pimecrolimus 1% cream. ^[5]
• Pimecrolimus suits a cream base, milder disease, or patients prone to local reactions. ^[5]
• Rough potency equivalence to TCS (an estimate, not a formal classification): pimecrolimus 1% is similar to a mild steroid such as hydrocortisone 1%; tacrolimus 0.03% to a moderate steroid such as clobetasone butyrate 0.05%; tacrolimus 0.1% to a potent steroid such as betamethasone valerate 0.1%. ^[4]
• A burning or stinging sensation is common for the first few days and then settles. ^[4]
• Tacrolimus may be used proactively twice weekly on problem areas once control is achieved to prolong remission. ^[4]
• A black box warning about cancer (particularly lymphoma) exists as a class; dedicated long-term studies identify lymphoma specifically, not cancer overall, as the increased risk, and the absolute risk remains low. ^[5]
• TCIs should be used as adjuncts with emollients, not as a replacement, and only on active eczema. ^[1]

NICE (through NICE CG57 and the NICE technology appraisal TA82 that it adopts) does not recommend TCI for mild eczema or as first-line for any severity: they are second-line, started only with specialist dermatological advice for adults or for children (from age 2 years) in whom further TCS use carries serious risk of side effects such as irreversible skin atrophy. ^[1] AAD recommends TCIs as first-line non-steroidal options in adults, applied several times weekly on quiescent disease to prevent flares. ^[5] These two positions are not identical; the practical message is "second-line in UK primary-care pathways, first-line as a non-steroidal anti-inflammatory in AAD guidance", with the same drug and the same cautions. ^[1][5]

Wet wrap therapy means applying a topical agent (an emollient or a low- or medium-potency TCS) to the skin, then a moistened first layer (cotton suit, gauze or bandages) and a dry outer layer. ^[5] AAD gives wet wraps a conditional recommendation for adults with moderate-to-severe atopic dermatitis during a flare, based on low-certainty evidence. ^[5] Duration can be as little as 1 hour up to a full day per session, and continued for up to several weeks. ^[5] Because occlusion increases steroid absorption, the duration should be limited when a TCS is used underneath, and wet wraps need patient education and time. ^[5] There is insufficient evidence to define the optimal method (vehicle, wrap material), and data on secondary infection risk are mixed. ^[5]

For children, UK guidance reserves wet wraps for short courses on lichenified or flaring areas, started by a specialist. ^[1] Emollients under wet wraps are also used when the skin is very dry.

AAD and Medscape summaries note newer options now used in atopic dermatitis: topical JAK inhibitors (ruxolitinib cream, capped at 20% of body surface area and 60 g weekly, short or intermittent courses only), PDE-4 inhibitors (crisaborole, roflumilast), and tapinarof cream, plus the aryl hydrocarbon receptor agonist tapinarof. ^[4][5] Systemic therapy and these agents belong to specialist or well-resourced settings; emollients and appropriate TCS remain the starting point for most patients worldwide.

Refer (or give same-day advice) in these situations, which recur across the UK and US guidance used here: ^[1][2][5]

• Severe eczema or severe life impact despite optimal topical therapy.
• Poor response after excluding infection, patch testing contact dermatitis, or reconsidering the diagnosis.
• Eczema herpeticum or suspected infected eczema not responding to treatment.
• Children with growth concerns, sleep disturbance or school impact.
• Disease on the face, eyelids or genitals requiring more than mild potency.
• Need for very potent steroids, occlusion therapy or wet wraps in children.
• Suspected topical steroid withdrawal.
• Diagnostic uncertainty, treatment failure with good adherence, or the condition not fitting the expected pattern.
• All patients who need treatment escalation beyond topical therapy (phototherapy, systemic or biologic agents) belong to specialist dermatology.

In practice this page itself is a "skills" topic: the safe prescribing of emollients and TCS is mostly a primary-care, nursing and pharmacy task, but the escalation points above are where specialist input earns its keep. ^[1][2]

Children need lower-potency steroids (mild on face and flexures, moderate on trunk and limbs), large emollient quantities, and close attention to TCS side effects such as growth suppression and skin thinning. ^[1][4][5] Potent TCS are not used under 12 months and very potent TCS never without specialist advice. ^[1] Growth monitoring is advised when large amounts of TCS are used. ^[1]

There is no age limit on TCS use and they are safe in pregnancy and breastfeeding, with potency and site limits still applying. ^[2] TCI safety in pregnancy is guided by the product label and specialist advice.

Thin skin and reduced dermal collagen with age and sun damage increase susceptibility to local adverse effects. ^[1] Prefer lower-potency TCS and generous emollient.

Most of this page needs no advanced equipment: recognise the inflammatory skin disease clinically, prescribe emollients in quantity, match TCS potency to severity and site, avoid prolonged very-potent steroids, and teach the fire-risk cautions. ^[1][6] Specialist drugs, patch testing and biologics may not be available locally; referral then becomes the most useful intervention.

Commonly linked topics include atopic dermatitis, contact dermatitis, psoriasis, lichen planus, lichen simplex chronicus, seborrhoeic dermatitis, skin infections such as impetigo, scabies and tinea, and the systemic treatments used when topical therapy is not enough. Atopic dermatitis in particular carries the full NICE CG57 stepped ladder that this page summarises for therapy.