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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Widespread blistering in a frail adult
Extensive erosions can cause pain, fluid loss, hypothermia, bacterial infection and rapid functional decline, while oral, ocular or genital disease may threaten intake, sight or urinary function.
Action: Assess observations, hydration, skin-failure extent, mucosa, pain and sepsis promptly; admit or arrange same-day dermatology when widespread disease, physiological compromise, immune suppression or unsafe home care is present.
Synopsis
Recognise the pruritic pre-bullous and tense-blister phases, obtain correctly paired biopsy specimens, stabilise frail patients, and select topical or systemic treatment with infection and steroid safeguards.
Bullous pemphigoid usually affects older adults and may begin with weeks or months of intense itch, urticarial plaques or excoriated eczema before any blister is visible.
Established blisters are tense because the split is subepidermal; they arise on normal or inflamed skin and are less easily ruptured than pemphigus bullae.
Mucosal disease can occur but is less dominant than in pemphigus vulgaris; extensive oral, ocular or genital involvement should widen the differential and increase referral urgency.
Key red flags
Fever, hypotension, confusion, rapidly spreading erythema, purulence, severe skin pain, extensive denudation, eye symptoms, dysphagia, inability to maintain intake or a recently started high-risk medicine requires urgent assessment for infection or another severe blistering disorder.
Secondary infection
Increasing pain, purulence, odour, spreading warmth, fever or confusion around erosions suggests bacterial complication and requires urgent reassessment.
Investigation priorities
01
Routine histology from a fresh blister edgeFirst step
Demonstrate the anatomical split and inflammatory pattern while preserving blister roof and adjacent skin.
Management branches
First diagnostic sequencePair morphology with two correctly handled biopsies
Tense blisters or otherwise unexplained severe pruritic plaques suggest autoimmune subepidermal disease.
Examine the entire skin and mouth, eyes and genital symptoms, photograph representative fresh lesions with consent and review medicines, neurological disease and infection risk.
Take a blister-edge specimen into formalin for routine histology and a separate normal-appearing perilesional specimen into the laboratory-specified immunofluorescence medium.
Preferred topical controlUse superpotent corticosteroid when delivery is feasible
Pemphigoid is confirmed or strongly supported and topical application can be performed safely over all active skin.
Key medicines
Clobetasol propionate 0.05% topical treatmentApply once daily in the dermatologist-calculated whole-body quantity, often within a supervised 10–30 g daily induction range for extensive disease, then taper according to cessation of new blisters.
DoxycyclineTake 100 mg by mouth twice daily as the selected initial systemic strategy, with an early review of new-blister control and tolerability.
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.