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ukmla 2026

Pemphigus Vulgaris

Autoimmune intra-epidermal blistering — FLACCID blisters + oral erosions, Nikolsky POSITIVE, IgG against desmogleins, potentially fatal untreated

Review date
reviewed 2026-04-05
Reading time
4 min read
Author
Dr Kola Tytler MBBS CertHE MBA MSt MRCGP
Dermatologyrarechronic
On this page
Condition details
Dermatology
rare
4 min read
reviewed 2026-04-05
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About This Page

This is a clinician-written, evidence-based summary aligned to the 2026 MLA Content Map. It is intended for medical students and junior doctors preparing for the UKMLA. Always cross-reference with NICE guidance, local protocols, and clinical judgement.

Key points

  • IgG against desmoglein 3 (mucosal) and desmoglein 1 (skin) — intra-epidermal acantholysis
  • FLACCID blisters that rupture easily leaving painful erosions. Nikolsky POSITIVE
  • Oral erosions in >90% — often the FIRST presentation
  • DIF: IgG in intercellular "chicken-wire" pattern — DIAGNOSTIC
  • Treatment: systemic immunosuppression — prednisolone + rituximab/azathioprine. Fatal if untreated

Overview

Pemphigus vulgaris is caused by IgG against desmogleins causing loss of intercellular adhesion (acantholysis) and intra-epidermal blisters. Blisters are fragile, rupturing easily. Oral erosions are the commonest presenting feature (>90%). Historically fatal within 2-5 years without treatment; modern mortality ~5-10%.

Epidemiology

Rare — ~0.5-3 per 100,000/year. Age 40-60. Higher in Ashkenazi Jewish and Mediterranean populations. Drug-induced pemphigus with ACE inhibitors and penicillamine.

Clinical Features

Symptoms
Painful, non-healing ORAL erosions — often first presentation (>90%)
FLACCID skin blisters that rupture easily leaving raw erosions
Widespread erosions with significant pain
Signs
Nikolsky sign POSITIVE
Asboe-Hansen sign: blister extends laterally with pressure
Oral erosions on buccal mucosa, palate — may not see intact blisters
Skin: flaccid blisters and widespread erosions on trunk, scalp

Investigations

First-line
Skin biopsy (lesional)Intra-epidermal acantholysis — tombstone basal cells
Direct immunofluorescence (perilesional)Intercellular "chicken-wire" IgG/C3 in epidermis — DIAGNOSTIC
Second-line
Anti-desmoglein 1 and 3 ELISATitre correlates with activity

Management

BAD Guidelines on Pemphigus
1
Systemic corticosteroids
  • Prednisolone 0.5-1 mg/kg/day
  • Taper slowly once controlled
2
Steroid-sparing agents
  • Rituximab (anti-CD20): increasingly first-line alongside steroids
  • Azathioprine or mycophenolate mofetil
  • Check TPMT before azathioprine
3
Supportive
  • Oral care: soft diet, antiseptic mouthwash
  • Wound care: non-adherent dressings
  • Nutritional support

Complications

  • Sepsis: Through denuded skin — historically leading cause of death
  • Fluid/protein loss
  • Immunosuppression complications
UKMLA Exam Tips
  • 1PV = FLACCID + Nikolsky POSITIVE + oral erosions + intra-epidermal + chicken-wire IgG
  • 2BP = TENSE + Nikolsky NEGATIVE + minimal oral + subepidermal + LINEAR IgG
  • 3Oral erosions as FIRST presentation of PV — blisters too fragile to see intact in mouth
  • 4Anti-desmoglein 3 = mucosal. Anti-desmoglein 1 = cutaneous. Both = mucocutaneous
  • 5Rituximab increasingly first-line for pemphigus
  • 6Acantholysis (loss of cell adhesion) on histology = hallmark of pemphigus

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Verified Sources & References

BAD — Pemphigus Guidelines
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