Educational draft · awaiting clinical reviewUse Rapid for revision, not patient-care decisions. Check current national and local guidance and the BNF or BNFC before acting.
2 min synopsisUK scopeSources checked 27 Aug 2026Clinical review pending
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Disseminated viral infection
Rapidly spreading painful monomorphic vesicles, punched-out erosions, fever, periocular disease or widespread varicella in a person applying a topical calcineurin inhibitor may represent eczema herpeticum or another serious viral infection rather than expected application burning.
Action: Stop application to infected skin, obtain urgent clinical and ophthalmic assessment where indicated, sample fresh lesions without delaying systemic antiviral treatment, and restart only after infection has resolved and the responsible clinician has reviewed the plan.
Synopsis
Use tacrolimus and pimecrolimus as steroid-sparing topical immunomodulators for supported indications, select age and strength correctly, counsel about burning, infection and ultraviolet exposure, and review non-response or persistent lesions safely.
Tacrolimus and pimecrolimus inhibit calcineurin-dependent T-cell signalling and cytokine release without causing corticosteroid skin atrophy.
They are not first-line treatment for ordinary atopic eczema: NICE positions them second line when appropriate topical corticosteroid control fails or serious atrophy risk is important.
Initiation should be by a clinician with a special interest and experience in dermatology after the diagnosis, severity, site and prior corticosteroid technique are confirmed.
Key red flags
Painful vesicles, punched-out erosions, fever, eye symptoms, spreading bacterial infection, persistent or unexplained lymphadenopathy, an indurated or ulcerated lesion, immune compromise outside the treatment plan, or major photosensitivity requires prompt reassessment before further application.
Focal tumour warning
A lasting indurated, ulcerated, bleeding or otherwise atypical lesion should be biopsied or referred rather than suppressed repeatedly with local immunomodulation.
Investigation priorities
01
Diagnosis and severity confirmationFirst step
Ensure a supported inflammatory diagnosis and treatment threshold before initiation.
02
Observed topical-treatment auditFirst line
Show that appropriate first-line corticosteroid and emollient care genuinely failed or carried serious risk.
Management branches
First-line eligibilityVerify the second-line indication
A topical calcineurin inhibitor is being considered for atopic eczema.
Confirm diagnosis, severity and sensitive-site burden and review a correctly delivered topical corticosteroid and emollient plan.
Establish inadequate control or a serious corticosteroid adverse-effect risk and have an experienced clinician select tacrolimus or pimecrolimus by age, site and severity.
Key medicines
Tacrolimus 0.03% ointmentFor ages 2–15 years with licensed atopic eczema, apply thinly twice daily for up to 3 weeks then once daily until clear; adults may use this strength when stepping down. Selected maintenance uses once daily on 2 non-consecutive days each week.
Tacrolimus 0.1% ointmentFor people aged 16 years and over, apply thinly twice daily to affected atopic-eczema skin until clear; use the product-guided step-down or twice-weekly non-consecutive maintenance schedule after response.
National guidance is shown before implementation-dependent detail. Typical adult dose examples remain subject to patient factors, contraindications and the live BNF or specialist protocol. Source check completed 27 Aug 2026; clinical approval remains outstanding.