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Health condition

Pemphigus, the serious blistering disease that needs urgent recognition.

Rare but serious - fragile blisters and painful mouth ulcers that demand prompt diagnosis and specialist-led treatment, not a wait-and-see approach.

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Why trust this guide

  • 01

    Editorial team

    Written by our editorial team from the UK sources listed on each page.

  • 02

    Sourced from guidance

    Checked against British Association of Dermatologists (BAD) guidance and peer-reviewed sources you can see at the end.

  • 03

    Current for 2026

    Reflects modern UK guidance including immunofluorescence diagnosis, steroid-sparing agents and rituximab.

Key facts

Pemphigus at a glance.

The essentials, in plain English - what it is, why it differs from pemphigoid, and how it’s treated in the UK today.

  • What it is

    A rare autoimmune blistering disease - antibodies attack desmoglein proteins that hold skin cells together, causing fragile blisters and erosions.

  • Main variant

    Pemphigus vulgaris is the most common form, often starting with painful mouth ulceration before skin involvement appears.

  • How it differs

    Blisters are flaccid and rupture easily, unlike the tense, intact blisters of the more common bullous pemphigoid.

  • Severity

    Can be life-threatening if extensive or untreated, due to the risk of infection and significant fluid loss through eroded skin.

  • Diagnosis

    Skin biopsy with direct immunofluorescence is essential, alongside serum anti-desmoglein antibody testing.

  • Treatment

    High-dose systemic corticosteroids first, then steroid-sparing agents or rituximab to induce and maintain remission.

Why this guide matters

A rare disease that punishes delay.

Pemphigus is uncommon, but the cost of a missed or late diagnosis is high. The three points below shape everything else on this page.

  • Mouth ulcers are often the first clue

    Persistent, painful oral ulceration - sometimes for weeks - can precede skin blisters and is frequently mistaken for something less serious.

  • Fragility, not intact blisters, defines it

    Because blisters rupture so easily, what’s actually seen is often widespread erosion rather than tidy, intact blisters - a key diagnostic clue.

  • Extensive disease behaves like a burn

    Large areas of skin loss carry the same infection and fluid-balance risks as a burns injury, which is why severe cases need hospital-based, MDT care.

How the diagnosis is made

From first ulcer to a confirmed diagnosis.

The steps a UK dermatology team will normally follow, in order - so you know what to expect and why urgency matters.

  1. 01

    Recognising

    Recognising the pattern

    Flaccid, easily ruptured blisters and erosions on skin and mucous membranes, often with mouth ulceration as the first sign.

  2. 02

    Recognising

    Nikolsky sign

    Gentle lateral pressure on apparently normal skin causes it to shear and shed - a classic bedside clue in pemphigus.

  3. 03

    Recognising

    Urgent dermatology referral

    Any suspected pemphigus warrants an urgent specialist opinion given the potential for rapid, serious deterioration.

  4. 04

    Confirming

    Skin biopsy with immunofluorescence

    A biopsy from the edge of a lesion sent for direct immunofluorescence shows the characteristic intercellular staining pattern - the essential confirmatory test.

  5. 05

    Confirming

    Serum anti-desmoglein antibodies

    Blood testing for anti-desmoglein 1 and 3 antibodies supports the diagnosis and helps track disease activity over time.

  6. 06

    Confirming

    Assessing extent and severity

    Mapping body surface area involvement and mucosal disease guides whether treatment can be managed as an outpatient or needs admission.

  7. 07

    Planning

    MDT and specialist commissioning

    Severe or extensive disease is managed by a specialist commissioned dermatology multidisciplinary team, sometimes with burns unit input.

Typical timeline: urgent referral to biopsy result within one to two weeks.

Symptoms

What pemphigus actually looks like.

Fragile blisters, raw erosions and often painful mouth ulcers. And the features that mean it’s time for urgent care.

  • Flaccid blisters

    Soft, thin-walled blisters that rupture easily - quite different from the tense blisters seen in bullous pemphigoid.

  • Widespread erosions

    Because blisters are so fragile, raw, painful erosions are often what is actually seen rather than intact blisters.

  • Painful mouth ulceration

    Often the very first sign - persistent, painful oral erosions that make eating and drinking difficult.

  • Positive Nikolsky sign

    Gentle lateral pressure on normal-looking skin causes it to slide and shed, a hallmark bedside finding.

  • Other mucosal involvement

    The nose, throat, eyes and genital mucosa can also be affected, adding to the discomfort and complexity.

  • Widespread skin involvement

    In severe disease, erosions can cover large areas of the body, mimicking a burns-type presentation.

  • Secondary infection

    Eroded, broken skin is highly vulnerable to bacterial and fungal infection, which needs active monitoring.

  • Red flag - extensive or systemic illness

    Fever, extensive erosions or signs of fluid loss mean urgent hospital assessment, not a routine outpatient wait.

Treatment

How pemphigus is treated in the UK.

High-dose corticosteroids to gain control, steroid-sparing agents or rituximab to hold it - all within a specialist MDT.

  • High-dose systemic corticosteroids

    The mainstay of initial treatment - oral or intravenous, brought down gradually once new blister formation stops.

  • Azathioprine

    A steroid-sparing immunosuppressant used to allow the corticosteroid dose to be reduced while maintaining control.

  • Mycophenolate mofetil

    An alternative steroid-sparing agent, particularly useful where azathioprine is not tolerated or suitable.

  • Rituximab

    Increasingly used and effective for both inducing and maintaining remission - now a standard option in specialist practice.

  • Wound care for erosions

    Extensive erosions are managed with burns-style dressing and wound care principles to protect fragile skin and reduce pain.

  • Infection monitoring and treatment

    Regular assessment for secondary bacterial or fungal infection, with prompt antimicrobial treatment when needed.

  • Hospital admission

    Severe or extensive disease is admitted for fluid balance, infection control and intensive wound care.

  • MDT specialist dermatology care

    Managed through a specialist commissioned service, potentially with burns unit input for the most severe presentations.

What this guide is based on

The sources behind every claim on this page.

UK national guidance and specialist society standards, current at the time of last review.

Key references

Guidelines and standards we relied on.

A quiet reminder

This guide is for information, not medical advice.

Your dermatologist knows your history and disease extent and can tell you which parts apply to you. If in doubt, get seen urgently.

  • British Association of Dermatologists (BAD). Guidance and patient information leaflet on pemphigus vulgaris.

  • British Association of Dermatologists (BAD). Service standards for the management of autoimmune blistering diseases.

  • European Academy of Dermatology and Venereology (EADV). Guidelines for the management of pemphigus vulgaris.

  • NHS England. Specialised commissioning for severe autoimmune blistering skin disease.

Red flags

When pemphigus needs urgent attention.

Pemphigus is rarely mild. These are the situations that mean same-day or emergency assessment, not a routine wait.

  • Extensive skin loss

    Erosions covering a large body surface area behave like a burns injury and need urgent specialist and often hospital-based care.

  • Fever or systemic illness

    May signal sepsis from broken, infected skin - needs same-day medical assessment.

  • Signs of dehydration

    Extensive fluid loss through eroded skin can cause dehydration and electrolyte disturbance, particularly in older patients.

  • Severe mouth or throat involvement

    Painful oral and pharyngeal ulceration that prevents adequate eating or drinking needs urgent review and nutritional support.

  • Eye involvement

    Ocular mucosal disease risks scarring and sight loss if not assessed and treated promptly by ophthalmology.

  • Rapid progression

    New blisters appearing quickly over days, or spreading disease despite treatment, warrants urgent specialist review.

  • Signs of infection in erosions

    Increasing pain, spreading redness, pus or odour from erosions may indicate secondary infection needing prompt treatment.

  • Steroid side effects

    High-dose, prolonged corticosteroid use needs monitoring for blood sugar, bone health, blood pressure and mood changes.

  • Suspected drug-induced pemphigus

    Certain medicines, including some blood pressure drugs and penicillamine, can trigger pemphigus-like disease - flag all current medicines to the team.

Living with it

Manageable long term, with steady specialist care.

Four things that make the biggest difference day to day - sticking with treatment, gentle mouth and skin care, and staying on top of reviews.

A quiet reminder

Most people reach durable remission with treatment.

With modern therapy, including rituximab, long remission is a realistic goal for most patients - it takes patience to get there.

  1. 01 Adherence

    Stick with the treatment plan

    Immunosuppressant doses are adjusted carefully over months - stopping or changing them without specialist advice risks a flare.

  2. 02 Mouth care

    Gentle oral hygiene

    Soft toothbrushes, alcohol-free mouthwash and a soft diet during flares help protect fragile mouth lining.

  3. 03 Skin care

    Protect fragile skin

    Avoid friction and tight clothing where possible, and follow wound care advice closely while erosions heal.

  4. 04 Monitoring

    Keep review appointments

    Regular blood tests and specialist follow-up track both disease activity and treatment side effects - don’t skip them.

Frequently asked

Everything we get asked about pemphigus.

Quick answers on diagnosis, steroids, steroid-sparing agents and rituximab.

  • What is pemphigus?

    A rare, serious autoimmune blistering skin disease in which antibodies attack desmoglein proteins that normally hold skin cells together. This causes fragile, easily ruptured blisters and painful erosions, and can be life-threatening if extensive or untreated.

  • How is pemphigus different from bullous pemphigoid?

    Pemphigus causes flaccid blisters that rupture easily, often starting in the mouth, while bullous pemphigoid causes tense, intact blisters that are usually more robust. They are distinct diseases with different antibody targets and, though related, are managed somewhat differently.

  • Why does mouth ulceration matter so much?

    Painful mouth ulceration is frequently the very first sign of pemphigus vulgaris, sometimes appearing weeks or months before skin blisters. Recognising it early can lead to a faster diagnosis and treatment.

  • How is pemphigus diagnosed?

    A skin biopsy with direct immunofluorescence is essential, showing a characteristic intercellular staining pattern. Serum anti-desmoglein antibody testing supports the diagnosis and helps monitor disease activity.

  • What does treatment involve?

    High-dose systemic corticosteroids are the mainstay of initial treatment, with steroid-sparing agents such as azathioprine or mycophenolate mofetil added to allow the steroid dose to come down. Rituximab is increasingly used and is effective for inducing and maintaining remission.

  • Is pemphigus dangerous?

    It can be, particularly when extensive or left untreated, because of the risk of infection and significant fluid loss through eroded skin. Severe or widespread disease often needs hospital admission and specialist multidisciplinary care, sometimes with burns unit input.

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