Topical Steroids

Related Subjects: |Nikolsky's sign |Koebner phenomenon |Psoriatic Arthritis |Psoriasis |Eczema/Dermatitis |Anatomy of Skin | Topical Steroids

🧴 Topical corticosteroids (topical steroids) - a practical UK guide

Topical corticosteroids are anti-inflammatory medicines applied to the skin to rapidly reduce erythema, itch, oedema, and scaling in steroid-responsive dermatoses (especially eczema and psoriasis). They bind intracellular glucocorticoid receptors and downregulate pro-inflammatory gene transcription (cytokines, adhesion molecules), while also causing superficial vasoconstriction - so redness and itch often improve quickly. The clinical skill is matching potency to (1) severity and diagnosis, (2) body site/skin thickness, and (3) age, then stepping down once controlled to minimise harm while maintaining barrier repair with emollients.

✅ When to use

• 🧒 Eczema flares (atopic, discoid, contact): reduce inflammation + itch → restore barrier and break the itch–scratch cycle.
• 🧩 Psoriasis (selected sites): reduce plaque inflammation and scaling (often paired with vitamin D analogues or keratolytics in practice).
• 🐜 Inflammatory bite reactions / lichen simplex (short courses): symptomatic control.
• 🚫 Not a moisturiser: steroids treat inflammation; emollients treat dryness/barrier dysfunction.

🎯 Choosing potency: site + age + severity

• 👁️ Face/eyelids/genitals/flexures: usually mild → moderate, short courses (higher absorption, higher atrophy risk).
• 🦶 Palms/soles or lichenified plaques: often need potent for short periods.
• 👶 Children: higher surface-area-to-weight ratio → greater systemic absorption risk; use the lowest effective potency and review early.
• 🩹 Occlusion (dressings, cling film): can massively increase absorption - use only if specifically advised.

🧠 How to apply (the “right place, right amount, right time” rule)

• 📍 Apply to inflamed skin only (red/itchy/thickened), in a thin shiny layer.
• 🗓️ Once daily is often enough for many preparations; follow product/local guidance and reassess response.
• 🧴 Keep emollients generous and regular; separate applications (commonly 20–30 minutes) to avoid dilution/spread.
• 🧼 Wash hands after (unless treating hands), avoid eyes/mucosa.

📏 Fingertip unit (FTU) - simple dosing that prevents under-treatment

Under-application is a common reason steroids “don’t work”. Teach FTUs early: it improves adherence, safety, and outcomes.

🪜 Duration and step-down strategy (how to stay safe)

• 🔥 Treat flares decisively, then step down (reduce potency and/or frequency) once controlled.
• 🧩 If it rebounds quickly, think: diagnosis wrong? adherence/FTU? infection? contact allergy? need steroid-sparing therapy?
• 🧴 Maintenance is mostly emollients + trigger control; some patients use intermittent “proactive” regimens (protocol/specialist-led).

⚠️ Adverse effects (and how good prescribing prevents them)

• 🧻 Local: skin atrophy (thin, shiny skin), striae, telangiectasia, purpura/bruising, acne/rosacea flares, perioral dermatitis, delayed healing.
• 🦠 Infection: can mask/worsen fungal, bacterial, viral infection (e.g. tinea incognito) - reassess if painful, crusted, rapidly spreading, or not improving.
• 👁️ Peri-ocular risk: prolonged eyelid use can contribute to glaucoma/cataract risk - keep short and cautious.
• 🧠 Systemic (rare but important): HPA-axis suppression / Cushingoid effects - risk rises with high potency, large areas, prolonged use, occlusion, and in children.

🚩 Red flags for review / referral

• ⏳ No improvement after an appropriate course with correct FTU dosing.
• 😣 Painful erosions, extensive weeping/crusting, systemic unwellness, or suspected eczema herpeticum (urgent same-day assessment).
• 🔁 Repeated need for very potent steroids, large-area use, or long-term face/genital steroid use.
• ❓ Diagnostic uncertainty (eczema vs psoriasis vs tinea): wrong diagnosis drives escalation and harm.

📚 Types of topical steroids by potency (UK examples)

Potency groupings are commonly listed as mild, moderate, potent, and very potent in UK formularies. The examples below reflect typical UK preparations; exact classification can vary by reference and formulation.

🗣️ Patient counselling (a one-minute script)

• 🧴 “Use your emollient every day - it prevents flares.”
• 🎯 “Use the steroid only on red/itchy patches, in the right FTU amount.”
• 🪜 “Once it’s clear, we step down or stop - don’t keep using it daily for weeks without review.”
• 🚩 “Come back if it’s painful, crusting, spreading, or not improving - it may be infection or a different diagnosis.”

📌 Reference

• BNF. Topical corticosteroids (Topical steroids). Adapted list of examples and strengths (Accessed January 2022).