Pemphigus vulgaris (PV) is a rare, potentially life-threatening autoimmune blistering disease caused by IgG autoantibodies against desmoglein 3 (Dsg3) ± desmoglein 1 (Dsg1), leading to intraepidermal acantholysis with flaccid blisters and erosions of the skin and mucous membranes. [1-2] Without treatment, mortality approaches 10% in the US, primarily from sepsis, fluid loss, and debilitation. [3]
1. History
- Onset and progression: Oral lesions are the first manifestation in 50–90% of patients; skin involvement may follow weeks to months later via "epitope spreading" [1][4]
- Oral symptoms: Painful erosions of buccal mucosa, palate, tongue, inner lips, and gingiva; pain ranges from mild discomfort chewing to inability to eat with rapid weight loss [1]
- Skin symptoms: Flaccid blisters that rupture easily → non-healing erosions and crusts; predilection for scalp, neck, axillae, upper trunk [1]
- Other mucosal involvement: Nasal (hemorrhagic crusts), pharyngeal, laryngeal (hoarseness in up to 40%), esophageal, genital, perianal [1]
- Timing: Chronic, progressive course without treatment; lesions heal without scarring but may leave prolonged hyperpigmentation in darker skin [1]
- Ask about: New medications (especially thiol- and phenol-containing drugs), recent infections, emotional stress, UV exposure, dietary changes [1][5]
2. Alarm Features
- Extensive denudation (>30% BSA) → risk of sepsis, fluid/electrolyte derangement, mimicking a burn patient
- Inability to eat or drink due to severe oral/pharyngeal erosions → dehydration, malnutrition
- Laryngeal involvement → airway compromise, hoarseness progressing to stridor [1]
- Secondary infection of denuded skin (bacterial, herpetic superinfection)
- Rapid progression of new blisters despite initial treatment
- Features suggesting paraneoplastic pemphigus: polymorphous mucocutaneous lesions, severe stomatitis, bronchiolitis obliterans → search for underlying neoplasm (lymphoma, thymoma) [6]
3. Medications
Drug triggers to exclude in all new diagnoses: [7-9]
- Thiol-containing drugs: Penicillamine (most common), captopril, bucillamine, cephalosporins
- Phenol-containing drugs: Rifampin, levodopa
- Others with significant pharmacovigilance signals: ACE inhibitors (lisinopril), hydroxychloroquine, piroxicam, hydrochlorothiazide, nifedipine, nivolumab (checkpoint inhibitors), imiquimod [7]
Treatment medications
- First-line: Systemic corticosteroids + rituximab (moderate-to-severe) [1][10]
- Steroid-sparing adjuvants: Azathioprine, mycophenolate mofetil (if rituximab unavailable/contraindicated) [1]
- Refractory disease: IVIG, cyclophosphamide, immunoadsorption [1]
Cautions
- Live vaccines are contraindicated during immunosuppressive therapy
- Screen for hepatitis B/C and HIV before rituximab; risk of progressive multifocal leukoencephalopathy (PML) [1]
- Check TPMT before azathioprine initiation
4. Diet
- Dietary triggers reported: Foods rich in thiols (garlic, onion, leek), phenols (black pepper, red chili pepper), and tannins (red wine, tea) may exacerbate disease [5][11]
- Avoid hard, spicy, acidic, or very hot foods that traumatize oral erosions [12]
- Soft, bland diet during active oral disease to maintain caloric intake
- Nutritional supplementation if oral intake is severely impaired; consider enteral feeding in severe cases
- Calcium and vitamin D supplementation for osteoporosis prophylaxis during chronic corticosteroid use [1]
5. Review of Systems
- Oral: Mouth sores, pain with eating/swallowing, bleeding gums, hoarseness
- Skin: New blisters, non-healing erosions, crusting, pruritus (less common)
- ENT: Nasal crusting/bleeding, sore throat, voice changes, dysphagia
- GU: Genital erosions, dysuria, dyspareunia
- Ophthalmologic: Conjunctival involvement (rare in PV, more common in paraneoplastic pemphigus)
- Constitutional: Weight loss, fever (suggests secondary infection), fatigue
- Systemic: Screen for associated autoimmune conditions (thyroid disease, myasthenia gravis, rheumatoid arthritis) [12]
6. Collateral History and Family History
- Family history: PV has a genetic predisposition linked to HLA-DRB104:02 and HLA-DRB114:01; low-titer anti-Dsg antibodies are found in ~50% of clinically unaffected first-degree relatives [1]
- Ethnic predisposition: Higher incidence in Ashkenazi Jewish, Mediterranean, South Asian, and Middle Eastern populations
- Collateral information: Medication history from pharmacy records; timeline of new drug exposures relative to symptom onset; occupational exposures (pesticides) [1]
- Social context: Emotional stress as a recognized trigger; impact on quality of life, ability to eat, and social functioning [11]
7. Risk Factors
- Genetic: HLA-DRB104:02, HLA-DRB114:01, and non-HLA polymorphisms (ST18, TNF-α) [1][11]
- Medications: Thiol drugs (penicillamine, captopril), phenol drugs, checkpoint inhibitors [7-8]
- Environmental: Pesticide exposure, UV radiation, ionizing radiation, burns, surgery, physical trauma [1]
- Infections: Herpes simplex virus, HHV-8, EBV may trigger or exacerbate [5][11]
- Emotional stress: Well-documented precipitant [11]
- Comorbidities increasing risk of relapse: High BSA involvement, high BMI, high PDAI at onset, treatment delay, persistently elevated anti-Dsg1/Dsg3 titers [13]
8. Differential Diagnosis
- Bullous pemphigoid — tense blisters (vs. flaccid), subepidermal split, anti-BP180/BP230 antibodies, typically elderly [1][8]
- Mucous membrane pemphigoid — chronic mucosal erosions with scarring (PV heals without scarring) [1]
- Herpes simplex virus — grouped vesicles on erythematous base, shorter duration, Tzanck smear with multinucleated giant cells [1]
- Oral lichen planus — Wickham striae, reticular white pattern, no flaccid blisters [1]
- Erythema multiforme / Stevens-Johnson syndrome / TEN — target lesions, acute drug reaction, full-thickness necrosis [1]
- Hailey-Hailey disease — flexural predilection, family history, no circulating anti-Dsg antibodies [1]
- Paraneoplastic pemphigus — polymorphous lesions, severe stomatitis, bronchiolitis obliterans, associated neoplasm [6]
- IgA pemphigus — neutrophilic infiltrate, IgA deposits on DIF [1]
- Impetigo — superficial crusted erosions, culture-positive for Staph/Strep [1]
9. Past Medical History
- Prior episodes of oral ulcers or blistering (often misdiagnosed for months)
- Associated autoimmune diseases: Thyroid disease, myasthenia gravis, rheumatoid arthritis, lupus erythematosus [12]
- 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, penicillamine
- Vaccination history (update before initiating immunosuppression) [1]
10. Physical Exam
- Skin: Flaccid, easily ruptured blisters on non-inflamed skin; widespread erosions with crusting; predilection for scalp, trunk, axillae [1]
- Nikolsky sign: Positive — lateral pressure on perilesional skin induces new erosion (characteristic but not pathognomonic) [1][8]
- Asboe-Hansen sign: Extension of blister with direct pressure
- Oral exam: Erosions on buccal mucosa, palate, tongue, gingiva; desquamative gingivitis; intact blisters are rarely seen orally because they rupture quickly [1][4]
- Other mucosal surfaces: Nasal, pharyngeal, laryngeal, genital, perianal erosions [1]
- Nails: Paronychia, nail dystrophy in extensive disease [1]
- Vital signs: Fever suggests secondary infection; tachycardia/hypotension in severe cases with fluid loss
- Assess BSA involvement for severity grading (PDAI scoring)
11. Lab Studies
Diagnostic
- Serum anti-Dsg3 ELISA (sensitivity ~97%, specificity ~98%) — positive in PV; titers correlate with disease activity [8][14]
- Serum anti-Dsg1 ELISA — positive in mucocutaneous PV and pemphigus foliaceus [1][8]
- Indirect immunofluorescence (IIF) on monkey esophagus — intercellular IgG staining pattern [1][15]
Pre-treatment baseline labs: [1]
- CBC with differential
- CMP (creatinine, electrolytes, liver enzymes, albumin, fasting glucose)
- Hepatitis B surface antigen, hepatitis B core antibody, hepatitis C antibody, HIV
- TPMT level (if azathioprine planned)
- Quantitative immunoglobulins (before rituximab)
- TB screening (QuantiFERON or PPD)
Monitoring
- Serial anti-Dsg1/Dsg3 titers to guide therapy and predict relapse [2][8]
- CBC, CMP periodically during immunosuppressive therapy
12. Imaging
- Imaging is generally not required for diagnosis of PV
- Chest X-ray: Baseline before immunosuppressive therapy; rule out TB
- CT chest/abdomen/pelvis: If paraneoplastic pemphigus is suspected, to identify underlying neoplasm (lymphoma, thymoma, Castleman disease)
- Esophageal involvement: EGD if dysphagia suggests esophageal pemphigus
13. Special Tests
Gold standard diagnostic tests
- Skin biopsy (lesional): Histopathology showing suprabasal acantholysis with "row of tombstones" pattern (basal keratinocytes attached to basement membrane but separated from each other) [8][16-17]
- Perilesional biopsy for direct immunofluorescence (DIF): Intercellular deposits of IgG ± C3 in a "chicken-wire" or "lace-like" pattern throughout the epidermis — this is the single most important diagnostic test [1][8][15]
Scoring systems
- Pemphigus Disease Area Index (PDAI): Standardized severity scoring; <15 = mild, 15–44 = moderate, ≥45 = severe [18]
- Autoimmune Bullous Skin Disorder Intensity Score (ABSIS)
Biopsy technique pearls
- Lesional biopsy: Take from the edge of an active blister (include blister edge and adjacent normal skin) for H&E [8]
- Perilesional biopsy: Take from clinically uninvolved skin adjacent to a lesion for DIF (in Michel's transport medium, NOT formalin) [8]
14. ECG
- Not routinely indicated for PV diagnosis
- Consider ECG if initiating high-dose corticosteroids (electrolyte monitoring) or in patients with cardiac comorbidities
- Monitor for hypokalemia-related ECG changes in patients with extensive skin loss and electrolyte derangement
15. Assessment
PV is a chronic, relapsing autoimmune blistering disease with significant morbidity and potential mortality. Key assessment points:
- Severity stratification using PDAI guides treatment intensity [18]
- Mucosal-dominant vs. mucocutaneous subtypes have different antibody profiles (anti-Dsg3 alone vs. anti-Dsg3 + anti-Dsg1) and clinical implications [2]
- Diagnostic delay is common — average delay of months from oral symptom onset to diagnosis, as oral erosions are frequently misdiagnosed as aphthous ulcers or lichen planus
- Complications: Secondary bacterial/viral infection (especially HSV), sepsis, fluid/electrolyte imbalance, malnutrition, steroid-related adverse effects, treatment-related immunosuppression
- Relapse rate: Up to 50% with corticosteroids alone; significantly reduced with first-line rituximab (~20% in year 1, much lower with maintenance infusions) [1][18]
16. Treatment Plan
Initial stabilization (ED/acute setting)
- Wound care: Gentle cleansing, non-adherent dressings, topical antibiotics for secondary infection
- Fluid resuscitation and electrolyte correction if extensive denudation
- Pain management (avoid NSAIDs if possible; consider acetaminophen, topical lidocaine for oral lesions)
- Nutritional support; soft/liquid diet or NG/enteral feeding if unable to eat
Definitive treatment — moderate-to-severe PV: [1][10][19]
- First-line: Rituximab 1000 mg IV on days 1 and 14 + short-term prednisone (0.5–1.0 mg/kg/day tapered over 3–6 months)
- 89–90% complete remission off corticosteroids at 24 months (RITUX 3 trial) [1][20]
- Maintenance rituximab infusions (500 mg at months 12 and 18) reduce relapse risk [1]
- If rituximab unavailable/contraindicated: Prednisone 0.5–1.5 mg/kg/day + azathioprine (2–3 mg/kg/day) or mycophenolate mofetil (2–3 g/day) [1]
- Refractory disease: IVIG (2 g/kg over 2–5 days), cyclophosphamide, immunoadsorption [1]
The PEMPHIX trial demonstrated rituximab was superior to mycophenolate mofetil in sustained complete remission, with fewer disease flares (6 vs. 44 over 52 weeks). [10]
Mild PV (PDAI <15)
Drug-induced pemphigus
17. Disposition
Admission criteria
- Extensive skin denudation (>30% BSA) or rapidly progressive disease
- Inability to maintain oral intake due to severe oropharyngeal involvement
- Signs of secondary infection/sepsis
- Hemodynamic instability, significant electrolyte derangement
- Need for IV pulse corticosteroids or initiation of rituximab infusion
- Suspected paraneoplastic pemphigus requiring urgent workup
Observation
- Moderate disease with new diagnosis requiring biopsy and initiation of therapy
- Patients with flares on existing therapy requiring dose adjustment
Discharge criteria
- Mild disease with established diagnosis and outpatient dermatology follow-up arranged
- Stable patients with adequate oral intake and no signs of infection
- Clear plan for outpatient rituximab infusion
Specialist consultation triggers
- Dermatology — all cases (essential for biopsy, DIF, and long-term management)
- Ophthalmology — if ocular involvement suspected
- ENT — laryngeal involvement, hoarseness
- Oncology — if paraneoplastic pemphigus suspected
- Wound care/burn center — extensive denudation
18. Follow Up / Return Precautions
Follow-up timing
- Dermatology within 1–2 weeks of diagnosis for biopsy results and treatment initiation
- Serial visits every 2–4 weeks during active disease; frequency decreases as remission is achieved
- Anti-Dsg1/Dsg3 titers monitored every 3–6 months to guide therapy and predict relapse [2][8]
- Patients with relapse predictors (baseline PDAI ≥45, anti-Dsg1 >20 IU/mL, or anti-Dsg3 >130 IU/mL at month 3) should receive additional rituximab at month 6 [18]
Return precautions — instruct patients to seek immediate care for:
- New blisters or rapidly worsening erosions
- Fever, chills, or signs of skin infection (increasing redness, warmth, purulent drainage)
- Inability to eat or drink
- Voice changes, difficulty breathing, or swallowing
- Signs of steroid side effects (severe mood changes, vision changes, bone pain)
Expected recovery course
- Disease control (no new blisters for 2 weeks, ~80% healing) typically achieved within weeks of treatment initiation [1]
- Complete remission off therapy achievable in ~90% with first-line rituximab at 2 years [1]
- Long-term follow-up of the RITUX 3 trial showed 72% disease-free survival at 7 years without additional rituximab after the initial protocol [21]
References
1. Pemphigus. — Schmidt E, Kasperkiewicz M, Joly P. Lancet. 2019.
2. Pemphigus, Bullous Impetigo, and the Staphylococcal Scalded-Skin Syndrome. — Stanley JR, Amagai M. The New England Journal of Medicine. 2006.
3. Research Advances in Pemphigus. — Anhalt GJ, Diaz LA. The Journal of the American Medical Association. 2001.
4. Oral autoimmune vesicobullous diseases: Classification, clinical presentations, molecular mechanisms, diagnostic algorithms, and management. — Leuci S, Ruoppo E, Adamo D, Calabria E, Mignogna MD. Periodontology 2000. 2019.
5. Pemphigus: Trigger and Predisposing Factors. — Moro F, Sinagra JLM, Salemme A, et al. Frontiers in Medicine. 2024.
6. Autoimmune Pemphigus: Difficulties in Diagnosis and the Molecular Mechanisms Underlying the Disease. — Simionescu O, Tudorache SI. Frontiers in Immunology. 2024.
7. A Comprehensive, Population Level Evaluation of Previously Reported Drug Triggers of Pemphigus Highlights Immunomodulatory Capacity as a Common Characteristic. — Baroukhian J, Seiffert-Sinha K, Sinha AA. Frontiers in Immunology. 2024.
8. Pemphigus. — Bystryn JC, Rudolph JL. Lancet. 2005.
9. Drug-Induced Pemphigus: A Systematic Review of 170 Patients. — Ghaedi F, Etesami I, Aryanian Z, et al. International Immunopharmacology. 2021.
10. Rituximab versus Mycophenolate Mofetil in Patients with Pemphigus Vulgaris. — Werth VP, Joly P, Mimouni D, et al. The New England Journal of Medicine. 2021.
11. Pemphigus: Etiology, Pathogenesis, and Inducing or Triggering Factors: Facts and Controversies. — Ruocco V, Ruocco E, Lo Schiavo A, et al. Clinics in Dermatology. 2013.
12. Pemphigus: Associations and Management Guidelines: Facts and Controversies. — Ruocco E, Wolf R, Ruocco V, et al. Clinics in Dermatology. 2013.
13. Pemphigus Relapse: Mechanisms, Risk Factors, and Agents Associated With Disease Recurrence. — Pathak GN, Agarwal P, Wolfe SM, et al. The Journal of Dermatology. 2024.
14. ELISA detection of anti‐desmoglein 1 and anti‐desmoglein 3 and indirect immunofluorescence in oral pemphigus: A retrospective study. — Petruzzi M, Lucchese A, Contaldo M, et al. Oral Diseases. 2022.
15. Interventions for Pemphigus Vulgaris and Pemphigus Foliaceus. — Martin LK, Werth V, Villanueva E, Segall J, Murrell DF. The Cochrane Database of Systematic Reviews. 2009.
16. Lymphocyte‐predominant lesional inflammatory infiltrates of the skin are associated with mucosal‐dominant phenotype in pemphigus. — Papara C, Danescu S, Rogojan L, et al. Journal of Cutaneous Pathology. 2023.
17. Correlation of desmoglein 1 and 3 immunohistochemistry with autoantibody levels and clinical severity in pemphigus. — Pradeep A, Eapen M, Jagadeeshan S, Kani K. Journal of Cutaneous Pathology. 2023.
18. Optimizing Pemphigus Management With Rituximab and Short-Term Relapse Predictors. — Hébert V, Hamwi S, Tancrède-Bohin E, et al. JAMA Dermatology. 2025.
19. First-Line Rituximab Combined With Short-Term Prednisone Versus Prednisone Alone for the Treatment of Pemphigus (Ritux 3): A Prospective, Multicentre, Parallel-Group, Open-Label Randomised Trial. — Joly P, Maho-Vaillant M, Prost-Squarcioni C, et al. Lancet. 2017.
20. Rituximab Is an Effective Treatment in Patients With Pemphigus Vulgaris and Demonstrates a Steroid-Sparing Effect. — Chen DM, Odueyungbo A, Csinady E, et al. The British Journal of Dermatology. 2020.
21. Sustained Remission Without Corticosteroids Among Patients With Pemphigus Who Had Rituximab as First-Line Therapy: Follow-Up of the Ritux 3 Trial. — Tedbirt B, Maho-Vaillant M, Houivet E, et al. JAMA Dermatology. 2024.