Pemphigus VulgarisMANAGEMENT

DERMATOLOGY PRESENTATIONS · 12 SECTIONS

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630 items

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Cardiovascular Presentations71▾

Respiratory Presentations52▾

Neurological Presentations83▾

Gastrointestinal Presentations74▾

Genitourinary and Reproductive Presentations48▾

Infectious Disease Presentations148▾

Trauma Presentations89▾

Toxicologic Presentations80▾

Psychiatric Presentations26▾

Musculoskeletal and Rheumatologic Presentations96▾

Dermatology Presentations23▾

Allergic contact dermatitis Bullous Pemphigoid Cutaneous Abscess DRESS syndrome Eczema Herpeticum Erysipelas Erythema multiforme Henoch-Schönlein purpura Herpes Zoster (Shingles)Herpetic Whitlow Hidradenitis suppurativa Paronychia Pediculosis (Lice)Pemphigus Vulgaris Pilonidal Abscess Pressure injury Psoriasis (acute flare)Psoriasis Flare Staphylococcal Scalded Skin Syndrome Stevens-Johnson Syndrome (SJS)Toxic Epidermal Necrolysis (TEN)Urticaria (acute)Warfarin-induced Skin Necrosis

Environmental and Exposure Presentations27▾

Hematologic and Oncologic Presentations36▾

Pediatric-Specific Presentations19▾

Endocrine and Metabolic Presentations45▾

ENT and Maxillofacial Presentations27▾

Ophthalmologic Presentations19▾

Obstetric Presentations23▾

Systemic and Miscellaneous Presentations17▾

01Approach to the Critical Patient/attcp49

Immediate priorities

›Airway threats

›Laryngeal and pharyngeal erosion causing airway compromise

›Hoarseness in up to 40% of patients with mucosal involvement

›Stridor indicates impending obstruction; immediate airway securing required

›Early anesthesia or critical care consultation for progressive hoarseness

›Inability to protect airway from pharyngeal erosions

›Suction oropharyngeal secretions pooling over raw mucosa

›Avoid oropharyngeal airways that traumatize friable mucosa

›Fluid and hemodynamic stability

›Massive fluid loss risk from extensive skin denudation

›Treat as burn equivalent when BSA involvement greater than 30%

›Insensible losses dramatically elevated with loss of epidermal barrier

›Hemodynamic targets

›Systolic blood pressure greater than 90 mmHg

›MAP greater than 65 mmHg

›Urine output greater than 0.5 mL/kg/hour

›IV access and fluid resuscitation

›Two large-bore IV lines; avoid skin trauma at IV sites

›Isotonic crystalloid for hemodynamic compromise

›Albumin supplementation if serum albumin less than 25 g/L

›Sepsis recognition

›Secondary infection of denuded skin is the primary mortality driver

›Bacterial superinfection; Staphylococcus aureus and gram-negative organisms most common

›Herpetic superinfection (eczema herpeticum) with disseminated HSV

›Sepsis criteria

›Fever or hypothermia plus tachycardia or leukocytosis with hemodynamic instability

›Lactate greater than or equal to 2 mmol/L indicates organ hypoperfusion

02History/hx62

Presentation pattern

›Onset and progression

›Oral lesions are the first manifestation in 50 to 90% of patients

›Skin involvement follows weeks to months later via epitope spreading

›Average diagnostic delay of months due to misdiagnosis as aphthous ulcers

›Oral symptoms

›Painful erosions of buccal mucosa, palate, tongue, inner lips, gingiva

›Pain ranging from mild discomfort chewing to inability to eat

›Rapid weight loss with severe oral involvement

›Skin symptoms

›Flaccid blisters rupturing easily to leave non-healing erosions and crusts

›Predilection for scalp, neck, axillae, upper trunk

›Lesions heal without scarring but leave prolonged hyperpigmentation in darker skin

›Other mucosal sites

›Nasal — hemorrhagic crusts, epistaxis

›Pharyngeal and laryngeal erosions with hoarseness in up to 40%

›Esophageal involvement causing dysphagia and odynophagia

›Genital and perianal erosions

›Conjunctival involvement rare in PV; more common in paraneoplastic variant

›Nail changes

›Paronychia and nail dystrophy in extensive disease

Risk factors and triggers

›Genetic predisposition

›HLA-DRB1 04:02 and HLA-DRB1 14:01 most strongly associated

›Non-HLA polymorphisms including ST18 and TNF-alpha also implicated

›Low-titer anti-Dsg antibodies in approximately 50% of unaffected first-degree relatives

›Ethnic predisposition

›Higher incidence in Ashkenazi Jewish, Mediterranean, South Asian, and Middle Eastern populations

›Medication triggers

›Thiol-containing drugs — penicillamine most common, captopril, bucillamine, cephalosporins

›Phenol-containing drugs — rifampin, levodopa

›ACE inhibitors, hydroxychloroquine, piroxicam, hydrochlorothiazide, nifedipine

›Checkpoint inhibitors — nivolumab and other PD-1/PD-L1 agents

›Imiquimod topical use reported as trigger

›Drug-induced pemphigus

›25% resolve with drug cessation alone

›75% require additional immunosuppressive treatment

›Environmental and infectious triggers

›Pesticide exposure and UV radiation

›Ionizing radiation, burns, surgery, and physical trauma as precipitants

›Herpes simplex virus, HHV-8, EBV may trigger or exacerbate

›Emotional stress — well-documented precipitant

›Dietary triggers — foods rich in thiols (garlic, onion, leek), phenols, and tannins

Alarm features

›Critical red flags requiring urgent escalation

›Extensive denudation greater than 30% BSA

›Risk of sepsis, fluid and electrolyte derangement mimicking burn patient

›Inability to eat or drink from severe oropharyngeal erosions

›Dehydration and malnutrition risk; enteral feeding may be required

›Laryngeal involvement with progressive hoarseness or stridor

›Airway compromise is life-threatening

›Secondary infection of denuded skin

›Bacterial: increasing erythema, warmth, purulent drainage

›Herpetic: vesicular clustering on erosion background

›Rapid progression of new blisters despite initial treatment

›Features suggesting paraneoplastic pemphigus

›Polymorphous mucocutaneous lesions, severe stomatitis, bronchiolitis obliterans

›Urgent search for underlying neoplasm — lymphoma, thymoma, Castleman disease

Past medical history and context

›Relevant prior history

›Prior episodes of oral ulcers or blistering often misdiagnosed for months

›Associated autoimmune diseases: thyroid disease, myasthenia gravis, rheumatoid arthritis, lupus

›History of thymoma or lymphoma raises concern for paraneoplastic pemphigus

›Prior herpes simplex infections — risk of eczema herpeticum on denuded skin

›Chronic medication use especially ACE inhibitors and penicillamine

›Vaccination history — update all vaccines before initiating immunosuppression

03Physical Exam/exam45

Skin exam

›Blister morphology

›Flaccid, easily ruptured blisters on non-inflamed skin

›Predilection for scalp, trunk, axillae, groin, perioral skin

›Widespread erosions with crusting and weeping

›Nikolsky sign

›Positive — lateral shear pressure on perilesional skin induces new erosion

›Characteristic but not pathognomonic for PV

›Asboe-Hansen sign

›Extension of blister with direct vertical pressure

›Indicates acantholysis is extending beyond visible blister edge

›BSA assessment

›Rule of Nines estimation of active erosion surface area

›Greater than 30% BSA involvement warrants ICU or burns-level care

›PDAI (Pemphigus Disease Area Index) for formal severity scoring

Mucosal exam

›Oral cavity

›Erosions on buccal mucosa, palate, tongue, gingiva

›Intact blisters rarely seen orally as they rupture immediately

›Desquamative gingivitis pattern on attached gingiva

›Posterior pharynx and soft palate erosions

›Assess swallowing function and gag reflex integrity

›Laryngeal and airway exam

›Hoarseness assessed by voice quality

›Progressive hoarseness demands direct or flexible laryngoscopy

›Stridor indicates critical airway involvement — immediate escalation

›Other mucosal surfaces

›Nasal mucosa — hemorrhagic crusts and erosions

04Differential Diagnosis/ddx42

Autoimmune blistering diseases

›Bullous pemphigoid

›ICD-10 L12.0

›Tense blisters on inflamed base versus flaccid blisters in PV

›Subepidermal split on histology versus suprabasal in PV

›Anti-BP180 and anti-BP230 antibodies; typically elderly patients

›Mucous membrane pemphigoid

›ICD-10 L12.1

›Chronic mucosal erosions with scarring versus PV which heals without scarring

›Subepidermal blister; linear IgG and C3 at basement membrane zone on DIF

›Pemphigus foliaceus

›ICD-10 L10.2

›Superficial scale and crust without mucosal involvement

›Anti-Dsg1 antibodies only; subcorneal acantholysis on histology

›IgA pemphigus

›Neutrophilic infiltrate; IgA deposits on DIF versus IgG in PV

›Subcorneal or intraepidermal pustular pattern

›Paraneoplastic pemphigus

›ICD-10 L10.81

›Polymorphous mucocutaneous lesions with severe stomatitis

›Bronchiolitis obliterans distinguishes from PV

›Associated neoplasm: lymphoma, thymoma, Castleman disease

Infectious and other mimics

›Herpes simplex virus oral and skin infection

›Grouped vesicles on erythematous base, shorter duration

›Multinucleated giant cells on Tzanck smear

›PCR positive for HSV

›Oral lichen planus

05Laboratory Tests/lt44

Serologic autoantibody testing

›Anti-desmoglein ELISA panel

›Anti-Dsg3 ELISA

›Sensitivity approximately 97%, specificity approximately 98% for PV

›Positive in all PV phenotypes (mucosal-dominant and mucocutaneous)

›Titers correlate with disease activity and guide treatment decisions

›Anti-Dsg1 ELISA

›Positive in mucocutaneous PV and pemphigus foliaceus

›Mucosal-dominant PV — anti-Dsg3 positive, anti-Dsg1 negative

›Mucocutaneous PV — both anti-Dsg3 and anti-Dsg1 positive

›Indirect immunofluorescence on monkey esophagus

›Intercellular IgG staining in a "chicken-wire" or "lace-like" epidermal pattern

›Screening test with high sensitivity; ELISA used to confirm and quantify

Pre-treatment baseline labs

›Infection screening before immunosuppression

›Hepatitis B surface antigen and hepatitis B core antibody

›HBV reactivation risk with rituximab requires antiviral prophylaxis if positive

›Hepatitis C antibody and HIV screening

›Tuberculosis screening

›QuantiFERON-TB Gold or tuberculin skin test before systemic immunosuppression

›Chest X-ray baseline

›Quantitative immunoglobulins before rituximab

›IgG less than 4 g/L increases infection risk; consider IVIG supplementation

›Metabolic and organ function

›Complete blood count with differential

›Baseline leukopenia or thrombocytopenia alters immunosuppressive strategy

›Hemoglobin for nutritional status assessment

›Comprehensive metabolic panel

06Diagnostic Tests/dt60

Scoring Systems

›Pemphigus Disease Area Index (PDAI)

›Validated composite score for pemphigus severity

›Skin component 0 to 250 (counts lesional sites on body surface)

›Scalp component 0 to 10

›Mucous membrane component 0 to 10

›Severity thresholds

›PDAI 0 — complete remission

›PDAI 1 to 8 — mild disease

›PDAI 9 to 24 — moderate disease

›PDAI greater than or equal to 25 — severe disease

›Clinical applications

›Baseline PDAI greater than or equal to 45 is an independent predictor of relapse

›Used to guide rituximab retreatment decisions in JAMA Dermatology 2025 protocol

›Autoimmune Bullous Skin Disorder Intensity Score (ABSIS)

›Alternative validated severity scoring instrument

›Incorporates BSA extent and lesion quality

›Less widely adopted than PDAI in clinical practice

›Treatment response definitions

›Disease control — no new blisters for 2 weeks with approximately 80% healing of existing lesions

›Complete remission off therapy — no disease activity without treatment for at least 2 months

›Relapse — reappearance of 3 or more new blisters per day lasting more than 2 days

MRI

›Role in pemphigus vulgaris workup

›Not routinely indicated for PV diagnosis or management

›No direct diagnostic role for skin or mucosal blistering assessment

›Paraneoplastic pemphigus evaluation

›MRI chest and mediastinum for thymoma characterization when CT identifies mass

07Disposition/dispo33

Admission indications

›Criteria for inpatient admission

›Extensive skin denudation greater than 30% BSA or rapidly progressive disease

›Signs of secondary infection or sepsis from denuded skin

›Hemodynamic instability or significant electrolyte derangement

›Inability to maintain oral intake

›Severe oropharyngeal involvement precluding adequate hydration and nutrition

›Laryngeal involvement with hoarseness or stridor

›Treatment initiation requirements

›IV pulse corticosteroids (methylprednisolone 500 to 1000 mg daily for 3 days)

›Rituximab infusion requiring monitored setting for infusion reactions

›New diagnosis requiring urgent biopsy

›DIF coordination requiring fresh tissue transport to immunopathology

›Suspected paraneoplastic pemphigus requiring urgent oncologic workup

Level of care determination

›ICU or burns unit criteria

›BSA involvement greater than 30% with fluid and electrolyte derangement

›Sepsis or septic shock from secondary wound infection

›Airway compromise requiring monitoring or intervention

›Dermatology ward criteria

›Moderate-to-severe disease requiring IV corticosteroids and wound care

›New diagnosis requiring rituximab infusion scheduling

›Flare on existing therapy requiring dose adjustment and monitoring

›Discharge criteria

›Mild disease with established diagnosis and confirmed outpatient dermatology follow-up

›Stable patients with adequate oral intake and no signs of infection

›Clear plan for outpatient rituximab infusion and corticosteroid taper

08Treatment/t97

Acute stabilization

›Wound care

›Gentle cleansing with non-irritating solutions

›Non-adherent dressings to minimize mechanical trauma at dressing changes

›Topical antibiotics for secondary bacterial infection of erosions

›Topical silver dressings for large denuded areas as in burn care

›Oral wound care

›Topical lidocaine 2% viscous for oral pain before meals

›Chlorhexidine 0.12% mouthwash for oral hygiene and infection control

›Avoid alcohol-containing oral rinses that traumatize mucosa

›Fluid and nutritional support

›Isotonic crystalloid for volume depletion from extensive denudation

›Albumin supplementation if serum albumin less than 25 g/L

›Daily electrolyte replacement guided by labs

›Nutritional support

›Soft bland diet during active oral disease to maintain caloric intake

›Nasogastric or nasojejunal feeding if oral intake is severely impaired

›Nutritional supplementation with protein targets 1.5 to 2 g/kg/day

›Calcium 1000 to 1500 mg/day and vitamin D 800 to 1000 IU/day for osteoporosis prophylaxis during corticosteroids

›Pain management

›Acetaminophen 500 to 1000 mg orally or IV every 6 hours for pain

›Avoid NSAIDs when possible — risk of triggering exacerbation in susceptible patients

›Opioids for severe pain from extensive cutaneous and mucosal erosions

›Topical lidocaine as adjunct for localized oral pain

First-line immunosuppressive therapy

›Rituximab plus short-term corticosteroids — moderate to severe PV

›Rituximab dosing (RITUX 3 protocol)

›Rituximab 1000 mg IV on day 1 and day 15

›Premedication: methylprednisolone 100 mg IV, diphenhydramine 25 to 50 mg IV, acetaminophen 650 mg orally 30 minutes before each infusion

›Infusion over 4 to 5 hours with vital signs monitored every 15 to 30 minutes

›Corticosteroid component

›Prednisone 0.5 to 1.0 mg/kg/day orally initiated concurrently

›Taper over 3 to 6 months as disease control is achieved

›Target prednisone 10 mg/day or less by 6 months when possible

›Outcomes from RITUX 3 trial (Lancet 2017)

›89% complete remission off corticosteroids at 24 months vs 34% with prednisone alone

›Class I recommendation for first-line rituximab in moderate-to-severe PV

›RITUX 3 long-term follow-up (JAMA Dermatology 2024)

›72% disease-free survival at 7 years without additional rituximab after initial protocol

›Maintenance rituximab

›500 mg IV at months 12 and 18 to reduce relapse risk

›Reduces relapse rate from approximately 50% to approximately 20% at year 1

›PEMPHIX trial evidence (NEJM 2021)

›Rituximab superior to mycophenolate mofetil in sustained complete remission

›6 disease flares with rituximab versus 44 flares with mycophenolate mofetil over 52 weeks

›Class I recommendation supporting rituximab over mycophenolate as first-line adjuvant

Alternative immunosuppressive therapy

›When rituximab is unavailable or contraindicated

›Prednisone 0.5 to 1.5 mg/kg/day plus azathioprine or mycophenolate mofetil

›Azathioprine 2 to 3 mg/kg/day orally after TPMT confirmation

›Dose reduction required for intermediate TPMT activity

›Check CBC at 2 weeks and monthly thereafter

›Mycophenolate mofetil

›2000 to 3000 mg/day orally in two divided doses

›Alternative if azathioprine not tolerated or TPMT deficient

›Teratogenic — reliable contraception mandatory

›Severe or acute presentation

›Pulse methylprednisolone 500 to 1000 mg IV daily for 3 consecutive days

›For rapidly progressive disease requiring rapid blister suppression

›Monitor blood glucose, blood pressure, and electrolytes during pulse therapy

›Transition to oral prednisone after pulse completion

Refractory disease management

›Intravenous immunoglobulin

›IVIG 2 g/kg total dose over 2 to 5 days per course

›Repeat cycles every 3 to 4 weeks until remission

›Mechanism: accelerated IgG catabolism via FcRn saturation reducing pathogenic antibody titers

›Pre-infusion IgA level to rule out IgA deficiency (risk of anaphylaxis)

›Indications: disease refractory to rituximab plus corticosteroids or contraindication to rituximab

›Cyclophosphamide

›Cyclophosphamide 1 to 2 mg/kg/day orally for severe refractory disease

›Monthly IV pulse 750 mg/m2 IV as alternative regimen

›Mesna uroprotection with IV pulse to prevent hemorrhagic cystitis

›Baseline and serial urinalysis; limit cumulative dose due to bladder and oncologic toxicity

›Immunoadsorption

›Protein A immunoadsorption to rapidly clear circulating autoantibodies

›Most rapid reduction in anti-Dsg antibody titers

›Reserved for life-threatening disease or as bridge to rituximab response

›Requires specialist center with plasmapheresis capability

Mild PV and drug-induced pemphigus

›Mild disease management

›Topical high-potency corticosteroids for localized disease

›Clobetasol propionate 0.05% cream or ointment twice daily to active lesions

›Topical tacrolimus 0.1% ointment as steroid-sparing agent for mucosal sites

›Escalate to systemic rituximab if no response within 3 months

›Drug-induced pemphigus

›Immediate discontinuation of offending drug

›25% resolve with drug cessation alone without immunosuppression

›75% require additional immunosuppressive treatment despite drug withdrawal

›Timeline to resolution after drug withdrawal: weeks to months

Infection prophylaxis during immunosuppression

›Antimicrobial prophylaxis

›Pneumocystis jirovecii prophylaxis

›Trimethoprim-sulfamethoxazole 80/400 mg daily while on prednisone greater than 20 mg/day for greater than 4 weeks

›Alternative: dapsone 100 mg daily or atovaquone 1500 mg daily if sulfa allergy

›HSV prophylaxis

›Valacyclovir 500 mg orally twice daily during intensive immunosuppression

›Acyclovir 400 mg twice daily as alternative

›Fungal prophylaxis

›Nystatin oral suspension or clotrimazole troches for oropharyngeal candidiasis prevention

›Vaccination

›All live vaccines contraindicated during active immunosuppressive therapy

›Administer inactivated influenza and pneumococcal vaccines before rituximab if possible

›Delay live vaccines minimum 6 months after rituximab

09Special Populations/sp71

Pregnancy

›Disease behavior during pregnancy

›PV can develop de novo during pregnancy or flare in pre-existing disease

›Neonatal pemphigus occurs in approximately 25 to 45% of babies born to mothers with active PV

›Transplacental IgG transfer causes transient neonatal skin and mucosal blistering

›Neonatal disease self-resolves within weeks as maternal antibodies are cleared

›Disease course

›Activity variable during pregnancy; no consistent pattern of improvement or worsening

›Postpartum flares are common even when disease was controlled during gestation

›Treatment in pregnancy

›Corticosteroids

›Prednisone is first-line and considered relatively safe; crosses placenta minimally

›Risk of gestational diabetes, hypertension, and preeclampsia with high doses

›Fetal growth restriction possible with prolonged high-dose use

›Rituximab

›Not recommended in pregnancy — crosses placenta in second and third trimesters

›Causes fetal B-cell depletion; delay pregnancy minimum 12 months after rituximab

›Contraindicated agents

›Mycophenolate mofetil — highly teratogenic; category X; reliable contraception required

›Cyclophosphamide — teratogenic in first trimester; avoid throughout pregnancy if possible

›Azathioprine — category D; used with caution when benefit exceeds risk

›IVIG

›IVIG 2 g/kg per cycle considered safe in pregnancy for refractory disease

›No teratogenic risk; preferred steroid-sparing adjuvant in pregnancy

›Multidisciplinary management

›Dermatology, maternal-fetal medicine, and neonatology co-management

›Neonatal team alerted at delivery for blister assessment and monitoring

›Breastfeeding — prednisone compatible; rituximab excreted minimally in breast milk but generally avoided

Geriatric

›Disease characteristics in older adults

›PV incidence peaks in sixth to seventh decade; mean age of onset 50 to 60 years

›Comorbidity burden increases mortality risk from treatment complications

›Differential diagnosis includes bullous pemphigoid which is far more common in elderly

›Diagnostic considerations

›Skin fragility in elderly increases risk of trauma-induced blisters mimicking PV

›Nikolsky sign may be positive due to skin fragility without PV

›DIF mandatory to distinguish from bullous pemphigoid and other disorders

›Treatment modifications

›Corticosteroids

›Heightened risk of steroid-induced osteoporosis, hyperglycemia, and hypertension

›Calcium 1500 mg/day and vitamin D 1000 IU/day from treatment initiation

›Bisphosphonate prophylaxis if anticipated corticosteroid duration greater than 3 months

›Blood glucose monitoring every 2 to 4 weeks during prednisone therapy

›Rituximab

›Generally well tolerated in older adults; major infection risk is the primary concern

›CD19 monitoring to confirm B-cell depletion; immunoglobulin monitoring for hypogammaglobulinemia

›Lower infectious threshold for empiric antimicrobials given depleted immune reserve

›Polypharmacy review

›Drug-induced pemphigus more likely in elderly with multiple concurrent medications

›Review all medications for thiol, phenol, ACE inhibitor, and checkpoint inhibitor triggers

Pediatrics

›Epidemiology in children

›PV is rare in children; less than 5% of all PV cases occur before age 18

›Presents similarly to adults with oral erosions preceding skin involvement

›Diagnosis delay common as pediatric clinicians have low suspicion

›Neonatal pemphigus

›Transient, self-limiting from maternal IgG transfer

›Resolves within 2 to 6 weeks without specific therapy in most cases

›Supportive wound care and feeding assistance during active phase

›Treatment considerations in children

›Corticosteroids

›Prednisone 0.5 to 1.0 mg/kg/day (maximum 60 mg/day)

›Growth monitoring and bone density surveillance with prolonged use

›Calcium and vitamin D supplementation throughout steroid therapy

›Rituximab in pediatric PV

›Case series support rituximab efficacy in children; dosing extrapolated from adult protocols

›Rituximab 375 mg/m2 IV weekly for 4 doses or two infusions of 750 mg/m2

›No pediatric RCT data; multidisciplinary pediatric dermatology guidance recommended

›Azathioprine in children

›1.5 to 2.5 mg/kg/day with TPMT genotyping before initiation

›Regular CBC monitoring for myelosuppression

›Psychosocial considerations

›Chronic blistering disease has significant impact on school attendance, peer relationships, and body image

›Child and adolescent mental health referral for significant quality-of-life impairment

10Background/b63

Epidemiology

›Incidence and prevalence

›Annual incidence 1 to 5 per million population in most countries

›Higher incidence in Ashkenazi Jewish populations: up to 32 per million

›Elevated incidence also in Mediterranean, South Asian, and Middle Eastern populations

›Demographics

›Mean age of onset 50 to 60 years; rare before age 20

›Female-to-male ratio approximately 1.5 to 2:1 in most series

›Mortality

›Prior to corticosteroids, mortality approached 75% within 5 years

›Modern mortality approximately 5 to 10% in the US; primarily from sepsis and treatment complications

›Rituximab era further reducing morbidity with 90% complete remission at 2 years

›Disease course

›Chronic relapsing-remitting course without treatment

›Relapse rate up to 50% with corticosteroids alone

›Relapse rate reduced to approximately 20% at year 1 with first-line rituximab

›Long-term RITUX 3 follow-up: 72% disease-free survival at 7 years

Pathophysiology

›Autoantibody mechanism

›IgG autoantibodies directed against desmoglein 3 (Dsg3) with or without desmoglein 1 (Dsg1)

›Desmogleins are transmembrane glycoproteins of the cadherin superfamily

›Function as cell-cell adhesion molecules in desmosomes of stratified epithelium

›Pathologic subtype determination by antibody profile

›Mucosal-dominant PV: anti-Dsg3 positive only — oral mucosa predominantly affected

›Mucocutaneous PV: anti-Dsg3 plus anti-Dsg1 positive — both skin and mucosae affected

›Dsg1 is more highly expressed in superficial layers of skin; Dsg3 predominates in mucosal epithelium

›Acantholysis mechanism

›Anti-Dsg antibodies disrupt desmoglein-mediated keratinocyte adhesion

›Results in intraepidermal acantholysis — loss of keratinocyte cohesion

›Suprabasal cleavage plane forms due to Dsg3 predominance in that layer

›Basal keratinocytes remain attached to basement membrane — tombstone pattern

›Secondary signaling

›Anti-Dsg3 antibodies activate intracellular signaling pathways beyond direct steric hindrance

›Src kinase, phospholipase C, and p38 MAPK pathway activation contribute to acantholysis

›Complement not required; direct antibody-induced keratinocyte separation is sufficient

›Genetic and immune pathogenesis

›HLA class II restricted disease — HLA-DRB1 04:02 and HLA-DRB1 14:01 alleles

›These alleles present Dsg3 peptides to autoreactive CD4+ T helper cells

›T-cell help drives B-cell class switching to IgG4 and IgG1 anti-Dsg antibodies

›Epitope spreading

›Initial anti-Dsg3 antibodies spread to additional Dsg3 epitopes and to Dsg1 over time

›Explains progression from mucosal-dominant to mucocutaneous phenotype

Therapeutic Considerations

›Rituximab mechanism and evidence

›Rituximab is an anti-CD20 monoclonal antibody depleting circulating B cells

›Eliminates B-cell precursors of anti-Dsg3 and anti-Dsg1 producing plasma cell clones

›Sustained B-cell depletion for 6 to 12 months after standard dosing

›Evidence hierarchy

›RITUX 3 (Lancet 2017): first-line rituximab superior to prednisone alone (89% vs 34% remission at 24 months)

›PEMPHIX (NEJM 2021): rituximab superior to mycophenolate mofetil as adjuvant (Class I)

›RITUX 3 long-term (JAMA Dermatology 2024): 72% disease-free survival at 7 years

›Steroid complications and mitigation

›Corticosteroid adverse effects are a major source of morbidity in PV management

›Osteoporosis, avascular necrosis, cataracts, glaucoma, diabetes, hypertension

›Rituximab's steroid-sparing effect is a major therapeutic advantage

›Bone protection protocol

›Calcium 1000 to 1500 mg/day plus vitamin D 800 to 1000 IU/day from corticosteroid initiation

›Bisphosphonate if prednisone course expected to exceed 3 months

›Baseline DEXA scan for patients anticipated to require prolonged corticosteroid therapy

›Monitoring anti-Dsg titers to guide therapy

›Rising titers often precede clinical relapse by weeks to months

›Preemptive rituximab retreatment based on titer rise may prevent overt relapse

›Anti-Dsg3 greater than 130 IU/mL at month 3 post-rituximab — additional infusion at month 6

›Disease control definition guides taper decisions

›No new blisters for 2 consecutive weeks with approximately 80% existing lesion healing

›Confirmed control before corticosteroid taper initiation reduces rebound flare risk

11Patient Discharge Instructions/pdi36

copy discharge instructions

›Diagnosis and disease understanding

›You have been diagnosed with pemphigus vulgaris, an autoimmune blistering disease

›Your immune system produces antibodies that attack the glue holding skin and mucous membrane cells together

›This is a chronic condition that requires ongoing treatment and specialist follow-up

›With modern treatment including rituximab, most patients achieve complete remission

›Skin and wound care at home

›Keep erosions clean by gently washing with mild non-perfumed soap and lukewarm water

›Apply prescribed non-stick dressings to open erosions; change as instructed

›Do not pick or forcefully remove crusts as this worsens erosions

›Wear loose-fitting soft clothing to minimize friction on affected skin

›Avoid tape and adhesives directly on fragile skin

›Oral care

›Rinse mouth twice daily with prescribed mouthwash (chlorhexidine or saline)

›Apply prescribed topical gel or rinse before meals to reduce oral pain

›Eat soft, bland foods; avoid spicy, hard, acidic, or very hot foods

›Avoid garlic, onion, red wine, and spicy seasonings that may worsen blisters in susceptible patients

›Maintain oral hygiene gently with soft toothbrush

›Medication instructions

›Take prednisone exactly as prescribed — do not stop suddenly without medical advice

›Stopping steroids abruptly can cause dangerous side effects

›Take calcium and vitamin D supplements daily as prescribed to protect your bones

›Take prescribed infection prevention medications as directed

›Avoid live vaccines (MMR, chickenpox, yellow fever, nasal flu vaccine) while on immunosuppression

›Activity and sun protection

›Avoid excessive sun exposure — UV radiation can trigger new blisters

›Apply SPF 50 or higher sunscreen to unaffected skin when outdoors

›Avoid physical trauma to skin — padding sharp edges, avoiding contact sports during active disease

12References/r28

Guidelines and key sources

›Primary clinical guidelines

›Schmidt E, Kasperkiewicz M, Joly P. Pemphigus. Lancet. 2019. PMID 31498102

›Comprehensive review: incidence, pathogenesis, diagnosis, and treatment

›Leuci S et al. Oral autoimmune vesicobullous diseases. Periodontology 2000. 2019

›Oral manifestations, DIF patterns, diagnostic algorithms

›Stanley JR, Amagai M. Pemphigus, bullous impetigo, and staphylococcal scalded-skin syndrome. NEJM 2006

›Pathogenesis of desmoglein autoantibodies and differential diagnosis

Landmark trials

›RITUX 3 trial

›Joly P et al. First-line rituximab combined with short-term prednisone versus prednisone alone. Lancet. 2017. PMID 28342637

›89% complete remission with rituximab plus prednisone at 24 months versus 34% with prednisone alone

›Tedbirt B et al. Sustained remission without corticosteroids following RITUX 3 protocol. JAMA Dermatology. 2024

›72% disease-free survival at 7 years without additional rituximab

›PEMPHIX trial

›Werth VP, Joly P, Mimouni D et al. Rituximab versus mycophenolate mofetil in pemphigus vulgaris. NEJM. 2021

›Rituximab produced 6 flares versus 44 flares with mycophenolate over 52 weeks

›Relapse prediction

›Hebert V et al. Optimizing pemphigus management with rituximab and short-term relapse predictors. JAMA Dermatology. 2025

›Baseline PDAI greater than or equal to 45, anti-Dsg1 greater than 20 IU/mL, or anti-Dsg3 greater than 130 IU/mL at month 3 predict relapse

›Drug-induced pemphigus

›Ghaedi F et al. Drug-induced pemphigus: systematic review of 170 patients. Int Immunopharmacol. 2021. PMID 33418246

›25% resolve with drug cessation alone; 75% require immunosuppression

›Baroukhian J et al. Comprehensive population-level evaluation of drug triggers of pemphigus. Front Immunol. 2024. PMID 39906745

›Immunomodulatory capacity as common characteristic of pemphigus drug triggers

›Trigger and predisposing factors

›Moro F et al. Pemphigus: trigger and predisposing factors. Front Med. 2024. PMID 38213911

›Environmental, infectious, and dietary triggers; HLA associations

Learn More: Pemphigus Vulgaris→

Comprehensive Clinical Review

Structured, evidence-informed, long-form analysis for deeper understanding.

Evidence & Review

Reviewed by SymptomDx Medical Team · Last reviewed August 18, 2026

SymptomDx is an educational tool for medical professionals. It does not replace clinical judgment. Verify all clinical data and drug dosages with authoritative sources.