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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Extensive mucocutaneous pemphigus
Painful oral, pharyngeal, ocular, genital or widespread skin erosions can prevent intake, compromise airway or vision, cause major fluid loss and permit rapidly invasive infection.
Action: Assess airway, eyes, swallowing, hydration, pain, body-surface loss and sepsis immediately; admit and obtain same-day dermatology plus ophthalmology, ENT or genital specialist care when critical sites or systemic compromise are present.
Synopsis
Recognise painful mucosal and fragile cutaneous erosions, confirm intercellular autoimmunity with paired tissue and serology, and deliver rituximab-based specialist treatment while preventing infection and nutritional decline.
Pemphigus vulgaris commonly begins with persistent painful oral erosions before skin disease; intact blisters may be rarely seen because the intraepidermal roof is fragile.
Skin lesions are flaccid bullae or irregular raw erosions on normal or erythematous skin, often affecting scalp, face, chest, back and pressure sites.
Gentle lateral pressure may extend an erosion, but Nikolsky sign is neither necessary nor specific and should not be repeatedly elicited on painful skin.
Key red flags
Dysphagia, hoarseness, dyspnoea, eye pain, photophobia, reduced vision, inability to drink, rapidly increasing erosions, fever, hypotension or disproportionate skin pain requires urgent escalation and reconsideration of SJS/TEN or infection.
Infection superimposed
New purulence, malodour, warmth, fever, hypotension or disproportionate pain suggests bacterial, candidal or herpetic complication rather than immune activity alone.
Investigation priorities
01
Routine histology from a fresh blister edgeFirst step
Show the level of epidermal separation and acantholytic keratinocytes.
Management branches
First diagnostic sequenceConfirm acantholysis before deep immunosuppression
Map mouth, eyes, nose, pharynx, genital skin and total cutaneous erosions, assess intake and sepsis and photograph fresh lesions with consent.
Obtain blister-edge tissue for routine histology and a separate intact perilesional sample for direct immunofluorescence before more treatment when clinically safe.
Preferred systemic inductionCombine licensed rituximab with a glucocorticoid taper
An adult has confirmed moderate-to-severe pemphigus vulgaris and no contraindication to B-cell depletion.
Key medicines
Rituximab intravenous infusionGive 1000 mg intravenously on day 1 and day 15 with tapering glucocorticoid; give 500 mg at months 12 and 18 and then every six months only if clinically needed.
Prednisolone with rituximab inductionUse the specialist severity-based oral regimen, commonly about 0.5 mg/kg daily in moderate or 1 mg/kg daily in severe disease, with a planned rapid response-led taper.
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.