Selecting potency and vehicle for topical corticosteroids

01Purpose and principlesWhat the treatment does and how it fits into care.

Topical corticosteroids bind intracellular glucocorticoid receptors and alter transcription of inflammatory mediators, reducing vasodilatation, oedema, cytokine signalling and immune-cell recruitment. They suppress inflammation but do not remove the cause of contact allergy, infestation, fungal infection or neoplasia. Begin with morphology and diagnosis, then grade activity using itch, warmth, oedema, exudation, fissure and thickness rather than colour alone. In richly pigmented skin, active disease may be violaceous, grey, deep brown or mainly papular, while post-inflammatory pigment can remain after inflammation has settled.

Selection is a five-part decision: potency, vehicle, amount, frequency and duration. Thin and occluded sites absorb more than palms or soles. Babies have greater surface-area-to-weight exposure, and a nappy acts as an occlusive dressing. Ointment increases hydration and penetration and is useful for dry plaques; cream evaporates and is practical where exudate or folds make grease unacceptable. Scalp solutions or lotions pass through hair. Patient preference matters because an elegant but unused formulation has no efficacy, yet convenience cannot justify a potent aerosol sprayed indiscriminately over normal skin.

Every prescription should name the body site, product, potency, daily frequency, fingertip-unit or gram quantity, treatment length and action when clear or worse. Show the label and ask the patient or caregiver to demonstrate one application. Record weekly usage and other steroid exposure from inhalers, nasal preparations and purchased products. At review, distinguish continued active inflammation from pigment change, telangiectasia, steroid acne, tinea incognito, contact allergy and withdrawal reaction before escalating.

Key points

Confirm an inflammatory corticosteroid-responsive diagnosis before prescribing; tinea, scabies, HSV, acne, rosacea and malignancy can worsen or become obscured under steroid.
Potency follows both inflammation and site: palms, soles and thick plaques may need more potency than face, eyelids, folds, genital skin or infant skin.
Mild, moderate, potent and very potent are pharmacological classes, not instructions to use the strongest available product until redness fades.
Ointment suits dry, thick or lichenified disease and contains fewer preservatives; cream is less occlusive and often more acceptable for moist, weeping or flexural areas.
Lotion, gel, foam or solution can reach hairy scalp and large areas more easily, but alcohol-containing products sting fissured skin and aerosols bring fire or inhalation concerns.
One adult fingertip unit is about 0.5 g and covers roughly two adult handprint areas; prescribe enough for body area and duration and verify the product actually used.
Apply to active disease, usually once daily when supported by the product and condition pathway; more frequent use rarely adds benefit but increases burden and exposure.
Occlusion, nappies, wraps, thin skin, broken barrier and extensive area markedly increase absorption and can convert an apparently local treatment into systemic exposure.
A short correctly selected course usually causes less harm than persistent undertreated inflammation; safety comes from explicit site, quantity, duration and review rather than vague steroid avoidance.
Topical steroid withdrawal reactions are uncommon and mainly reported after prolonged frequent use of moderate or stronger products, especially on face or genital skin; do not confuse them with ordinary relapse, infection or contact allergy.

02Indications, selection and cautionsWho may benefit, who needs urgent treatment and important alternatives.

Dry thick inflammatory plaque

Scale, lichenification and fissuring on trunk or limb generally favours an ointment vehicle, with potency selected from site, diagnosis and severity.

Moist or weeping surface

Exudation, maceration or a hair-bearing area may make a cream, lotion or solution more usable, while infection must be excluded before steroid monotherapy.

Sensitive-site disease

Eyelid, face, flexural, genital and infant skin is thin or occluded and needs lower potency, shorter courses and earlier review than a palm or sole.

Steroid atrophy

Shiny thin skin, telangiectasia, easy bruising, striae and prominent vessels arise after excessive potency, duration or occlusion and can become irreversible.

Tinea incognito

A spreading asymmetric annular or pustular eruption with muted scale after steroid use suggests dermatophyte infection whose border has been altered.

Periorificial or rosacea-like harm

Papules around mouth, nose or eyes, facial burning and telangiectasia can be provoked or sustained by inappropriate facial corticosteroid use.

Systemic absorption signalRed flag

Growth slowing, weight gain, Cushingoid features, hypertension, muscle weakness or collapse after withdrawal raises hypothalamic–pituitary–adrenal suppression.

Red flags requiring action

Systemic illness, painful vesicles or erosions, purpura, rapidly advancing infection, visual symptoms after periocular use, marked skin atrophy, growth faltering, Cushingoid change, prolonged use over a large or occluded area, or systemic symptoms after sudden cessation requires urgent clinical review.

03Assessment before treatmentTests and checks that guide safe selection.

Investigation order

Read from the initial assessment onwards. Tests may run in parallel in urgent care; first-line, preferred, confirmatory, definitive and gold-standard labels appear only when the chapter explicitly states them.

01
Morphology and full-site examinationFirst step
Why
Confirm a steroid-responsive inflammatory diagnosis and exclude infection or tumour.
Interpretation and limitations
Inspect active edge, nails, scalp, folds and mucosa as relevant; unilateral progression, ulceration, nodularity or treatment resistance requires sampling or biopsy rather than stronger steroid.
02
Potency and product reconciliation
Why
Identify the actual corticosteroid strength, vehicle and all duplicate exposure.
Interpretation and limitations
Read tube and dispensing label, include online or borrowed products and inhaled or nasal steroid, and avoid inferring potency from brand colour or packaging.
03
Fingertip-unit and area calculation
Why
Prescribe enough medicine while limiting unplanned exposure.
Interpretation and limitations
Map active body areas and translate them into age-appropriate fingertip units or grams per application and course; unexplained excess or scarcity signals a technique or access problem.
04
Mycology, bacterial culture or HSV PCR
Why
Investigate infection when a treated eruption spreads, pustulates, crusts or becomes painful.
Interpretation and limitations
Sample an active fungal edge, purulent focus or fresh vesicle before treatment where safe; systemic illness or eczema herpeticum is treated without awaiting results.
05
Patch testing
Why
Diagnose allergic contact dermatitis to a corticosteroid, preservative, fragrance or accompanying product.
Interpretation and limitations
Specialist testing uses corticosteroid markers and the patient's products; apparent class failure may be allergy to vehicle or steroid molecule rather than inadequate potency.
06
Morning cortisol and adrenal assessment
Why
Evaluate clinically plausible suppression after high cumulative topical exposure.
Interpretation and limitations
Endocrinology selects morning cortisol, stimulation testing and a safe taper or stress-dose plan; random testing in ordinary short-course use is unnecessary.

04Treatment approachPreparation, options, escalation and aftercare.

01First-line selectionMatch disease, site and vehicleFirst stepFirst lineA corticosteroid-responsive inflammatory eruption requires local treatment.

1Confirm diagnosis and activity, map body sites and check age, pregnancy, infection, barrier damage, previous response and every current topical product.
2Choose the lowest potency likely to control that severity at that site and select ointment for dry thick skin, cream for moist or cosmetically important areas, or lotion or solution for hair-bearing skin.
3Write one measurable course with site, fingertip units or grams, frequency, duration and stop or step-down instruction and demonstrate application.

02Sensitive-site routeReduce absorption without undertreatingDisease affects face, eyelid, fold, genital skin, an infant or another thin or occluded site.

1Use a disease-specific mild or moderate product for the shortest effective course and avoid potent or very potent unsupervised treatment.
2Separate treatment of active skin from emollient, avoid unplanned wraps or nappy occlusion and review within days to weeks rather than issuing open repeats.
3If frequent relapse demands repeated exposure, confirm diagnosis and technique and consider a steroid-sparing or proactive specialist plan.

03Poor-response routeReassess before increasing potencyA correctly prescribed course appears ineffective or the eruption worsens.

1Observe application, count remaining medicine and verify the right tube, body site and duration before assuming pharmacological failure.
2Re-examine for tinea, HSV, scabies, bacterial infection, contact allergy, psoriasis, acneiform harm, neoplasia and inactive residual pigment.
3EscalationObtain targeted scraping, swab, patch testing or biopsy and escalate diagnosis-specific care rather than adding a fixed steroid–antimicrobial combination blindly.

04Long-exposure safetyReduce cumulative harm deliberatelyPotent treatment has been frequent, prolonged, extensive or occluded, or toxicity is suspected.

1Quantify weekly grams, duration, sites and all other steroid routes and examine for atrophy, infection, growth or Cushingoid change.
2Seek dermatology or endocrinology advice for a planned reduction and adrenal testing when exposure or symptoms justify it; do not abruptly stop if systemic suppression is plausible.
3Provide written flare and emergency instructions and report a serious suspected adverse reaction through the Yellow Card scheme.

05Regimens, contraindications and interactionsTreatment details and the circumstances that modify them.

Mild anti-inflammatory option for selected sensitive sites and mild disease where stronger preparations would create disproportionate risk.

Hydrocortisone 1% mild corticosteroid

Apply a thin measured layer once or twice daily to the prescribed active site for the defined short course; use age- and condition-specific limits and stop or step down when control is achieved.

Do not use indefinitely on eyelids or genitals, beneath an occlusive nappy or over untreated fungal, bacterial or herpetic infection. Product formulation and licensing differ by age and site.

Moderate-potency treatment when mild steroid is insufficient and anatomy permits greater potency without moving to a potent agent.

Clobetasone butyrate 0.05% moderate corticosteroid

Apply thinly once or twice daily to a clearly mapped area for the condition-specific short course, measuring quantity by fingertip units and reviewing before repeat use.

Avoid unreviewed facial, flexural, genital or infant use and unnecessary occlusion; monitor for atrophy, acneiform change, infection and contact allergy.

Potent suppression for appropriately severe or thick inflammatory disease where a lower class is unlikely to control activity.

Betamethasone valerate 0.1% potent corticosteroid

Apply a thin layer once daily or at the licensed frequency to active trunk, limb, scalp or thick-site disease for a defined course, then stop, step down or use only the prescribed proactive schedule.

Not a routine face, fold or genital product. Large area, broken skin and wraps increase systemic absorption; check the exact concentration because related formulations can occupy different potency classes.

Very potent rescue or induction for selected severe, thick or sclerosing dermatoses when safer classes are inadequate.

Clobetasol propionate 0.05% very potent corticosteroid

Under specialist or explicit disease-specific direction, apply sparingly once or twice daily for a short course; the SmPC limits a course to 4 weeks and total adult use to no more than 50 g per week unless specialist instructions impose a lower limit.

Exclude infection and focal malignancy, avoid routine thin-site use and monitor local and adrenal toxicity. Review promptly if the course approaches limits or repeated courses are required.

06Complications, monitoring and follow-upAdverse effects, response and longer-term review.

Review early enough to confirm reduced itch, warmth, thickness and exudation and do not judge activity from persistent hyperpigmentation or hypopigmentation alone.
Check tube, potency, vehicle, body-site map, frequency and grams used and ask the patient or caregiver to demonstrate application.
Inspect for atrophy, telangiectasia, striae, bruising, acneiform change, periorificial dermatitis and infection before authorising repeat potent treatment.
For children on repeated courses, track growth and total surface-area exposure and review all inhaled, nasal and topical steroid routes.
Escalate persistent unilateral, ulcerated, indurated or treatment-resistant lesions for mycology, patch testing or biopsy rather than renewing automatically.
Give same-day advice for painful vesicles, fever, spreading warmth, visual symptoms, systemic weakness or collapse after reducing prolonged high exposure.

07Special situationsVariants, exceptions and circumstances that change the usual approach.

Vehicle changes delivery

An ointment hydrates stratum corneum and usually increases penetration, while a lotion can improve coverage through hair despite carrying different irritants.

Occlusion changes the dose

Wraps, folds and nappies increase hydration and absorption, so the same tube behaves differently on an exposed forearm and beneath a nappy.

Potency is product specific

The corticosteroid molecule, concentration and formulation determine class; brand familiarity or percentage alone cannot safely substitute for checking the product.

Pigment outlasts inflammation

Residual light or dark colour may remain for months, and continued potent treatment of smooth asymptomatic pigment change only adds toxicity.

Relapse is not always withdrawal

Return of the original dermatosis after a short course is common; burning confluent spread beyond treated sites after prolonged misuse requires a wider differential.

Quantity reveals feasibility

A tiny tube cannot cover widespread disease, while unexpectedly high collection may reveal duplicate prescriptions, wrong-site use or stockpiling.

08Common pitfallsFrequent interpretation and management errors.

01
Selecting potency from redness alone and underestimating activity in brown or black skin.
02
Using a potent product on eyelids, folds or infant skin because it worked on a thick limb plaque.
03
Writing apply as directed without a site, quantity, duration or review point.
04
Calling poor adherence before checking that enough acceptable vehicle was prescribed for the surface area.
05
Escalating steroid potency over tinea incognito, scabies, HSV or a persistent tumour.
06
Using a fixed steroid–antifungal or steroid–antibiotic repeatedly without confirming both indications.
07
Diagnosing topical steroid withdrawal whenever ordinary eczema relapses, or dismissing systemic symptoms after abrupt cessation of genuinely high exposure.
08
Treating post-inflammatory pigment change as ongoing inflammation indefinitely.