Pemphigus vulgaris is a rare, potentially life-threatening autoimmune disease in which the immune system produces antibodies that attack the proteins holding skin cells together, causing painful blisters and erosions on the skin and mucous membranes. Before corticosteroids became available, the disease was almost uniformly fatal. Today, with aggressive immunosuppression and newer targeted therapies, most people achieve remission, though treatment can be prolonged and carries its own risks. The biology behind pemphigus vulgaris is better understood than that of many autoimmune diseases, and this understanding has recently opened the door to strikingly precise therapies.
What Goes Wrong at the Cellular Level
The blisters in pemphigus vulgaris arise because the immune system generates antibodies (specifically IgG class) against desmoglein 3 and, in many patients, desmoglein 1. Desmogleins are adhesion proteins that sit on the surface of keratinocytes and essentially rivet neighboring skin cells to one another through structures called desmosomes. When autoantibodies bind these proteins, the rivets fail. Cells peel apart from each other in a process called acantholysis, and fluid fills the resulting gap, producing a blister.1PubMed Central. Mechanisms Causing Acantholysis in Pemphigus-Lessons from Human Skin
Tissue samples from pemphigus vulgaris lesions show a characteristic pattern: desmosomes are smaller and fewer in number, keratin filaments that normally anchor into desmosomes pull away, and “split desmosomes” appear where the structure has partially broken apart. These microscopic hallmarks are what make a skin biopsy so useful in confirming the diagnosis.
Clinical Phenotypes and How Antibodies Shape Them
Not every patient with pemphigus vulgaris looks the same. Clinicians recognize three broad phenotypes based on where blisters appear: mucosal-dominant, mucocutaneous, and cutaneous. The phenotype tracks closely with which desmogleins the patient’s antibodies target. In mucosal-dominant disease, antibodies attack desmoglein 3 almost exclusively, so blisters concentrate in the mouth, throat, and sometimes the genitals or eyes. In mucocutaneous disease, antibodies go after both desmoglein 3 and desmoglein 1, and patients develop blisters on both mucous membranes and skin surfaces. A study of pemphigus sera found that patients with mucosal-dominant disease were uniformly negative for anti-desmoglein 1 antibodies but positive for anti-desmoglein 3, while those with mucocutaneous disease tested positive for both.2PubMed. The clinical phenotype of pemphigus is defined by the anti-desmoglein autoantibody profile
This correlation is strong but not perfect. A separate study found that close to half of patients with confirmed pemphigus vulgaris did not have the phenotype their antibody profile would predict.3PubMed. A comparison of anti-desmoglein antibodies and indirect immunofluorescence in the serodiagnosis of pemphigus vulgaris Other factors, including the relative concentrations of desmoglein 1 and desmoglein 3 in different tissues and possibly non-desmoglein antibodies, likely contribute to where blisters actually form. In an Iranian cohort, patients with the mucocutaneous type had significantly higher anti-desmoglein 1 levels than those with mucosal disease, and their anti-desmoglein 3 levels were also the highest among all three phenotypes.4PubMed. Desmoglein 1 and 3 enzyme-linked immunosorbent assay in Iranian patients with pemphigus vulgaris: correlation with phenotype, severity, and disease activity The takeaway is that the antibody profile gives clinicians a reasonable guide to what to expect, but it is not the whole story.
How Pemphigus Vulgaris Is Diagnosed
The disease often starts insidiously. Mouth sores that do not heal are the first symptom for many patients, sometimes persisting for weeks or months before anyone suspects pemphigus. Eventually, flaccid, thin-walled blisters appear on the skin; they rupture so easily that a patient may never see an intact blister and instead presents with raw, painful erosions. A classic bedside test involves pressing laterally on the edge of a blister or on apparently normal skin near a lesion. If the outer layer of skin slides off under gentle pressure, that is a positive Nikolsky’s sign, a finding closely associated with pemphigus and a handful of other severe blistering conditions.5PubMed Central. Nikolsky’s sign: A pathognomic boon
Confirming the diagnosis requires tissue and blood work. A skin biopsy from the edge of a blister shows the characteristic intraepidermal split with acantholysis. A second biopsy, taken from uninvolved skin near a lesion, undergoes direct immunofluorescence, a technique that uses fluorescent-labeled reagents to detect antibody deposits within the tissue. In pemphigus vulgaris, this typically reveals IgG deposited in a lattice-like pattern between keratinocytes. Direct immunofluorescence is considered essential for diagnosing blistering skin diseases and provides critical confirmation that standard histology alone cannot.6PubMed Central. Direct Immunofluorescence of Skin and Oral Mucosa: Guidelines for Selecting the Optimum Biopsy Site
Blood tests using ELISA can measure the levels of anti-desmoglein 1 and anti-desmoglein 3 antibodies circulating in the patient’s serum. These are valuable not just for initial diagnosis but also for monitoring disease activity over time, as antibody levels tend to rise and fall in parallel with flares and remission.7British Journal of Dermatology. Monitoring disease activity in pemphigus with enzyme‐linked immunosorbent assay using recombinant desmogleins 1 and 3 Anti-desmoglein 1 levels appear to be especially useful for gauging the extent of skin disease in the mucocutaneous phenotype.8PubMed Central. Evaluation of desmoglein 1 and 3 autoantibodies in pemphigus vulgaris: correlation with disease severity
Genetic Susceptibility
Pemphigus vulgaris is not inherited in a simple pattern, but genetics clearly load the dice. The strongest associations are with specific variants in the HLA (human leukocyte antigen) genes, which encode proteins the immune system uses to present fragments of molecules to T cells. Certain HLA alleles appear across multiple populations studied, while others are population-specific. A study of Vietnamese patients identified a set of HLA-DRB1 and DQB1 alleles that increased susceptibility and another set that appeared protective.9PubMed Central. HLA-DRB1 and DQB1 genetic susceptibility to pemphigus vulgaris and pemphigus foliaceus in Vietnamese patients Similar findings have emerged in studies of other ethnic groups, with DRB1*04 and DRB1*14 variants frequently appearing as risk factors. These alleles may shape the immune response in a way that makes tolerance to desmogleins more fragile, though the exact chain of events from gene to autoantibody remains under investigation.
Having a risk allele does not mean you will develop the disease. Pemphigus vulgaris remains rare even in high-risk populations, which points to the necessity of additional triggers.
Triggers and Exacerbating Factors
A range of environmental exposures has been linked to the onset or worsening of pemphigus vulgaris. These include certain medications, particularly drugs containing thiol groups (such as penicillamine and captopril) or phenol groups, as well as infections, vaccines, emotional stress, physical trauma, pesticide exposure, and even dietary factors rich in thiols, phenols, or tannins.10PubMed Central. Pemphigus: trigger and predisposing factors Drug-induced cases can sometimes remit if the offending medication is stopped, though this is not guaranteed. For most patients, no single trigger can be pinpointed with certainty, and the disease likely results from an unlucky convergence of genetic predisposition and environmental exposure.
Treatment With Corticosteroids and Conventional Immunosuppressants
Systemic corticosteroids remain the backbone of initial treatment. The goal is to suppress the overactive immune response quickly enough to stop new blisters from forming and allow existing erosions to heal. Once the disease is under control (the “consolidation phase”), doses are tapered gradually. European guidelines recommend reducing the steroid dose by about a quarter every two weeks, then slowing to smaller reductions once the dose is low.11PubMed Central. Management of pemphigus vulgaris: challenges and solutions
Because long-term steroids cause serious side effects, including osteoporosis, diabetes, weight gain, and increased infection risk, steroid-sparing agents are usually introduced early. Azathioprine and mycophenolate mofetil are the most common first-line options. If the disease relapses during tapering, clinicians may increase the steroid dose temporarily, add or switch the immunosuppressant, or consider more aggressive options. Early diagnosis and prompt treatment consistently lead to better outcomes and lower mortality.12PubMed. Pemphigus vulgaris: a review of treatment over a 19-year period
Rituximab Has Changed the Treatment Landscape
The introduction of rituximab, an antibody that depletes B cells (the immune cells responsible for producing autoantibodies), has been the most significant advance in pemphigus treatment in decades. In a landmark trial, roughly nine out of ten patients treated with rituximab plus a short course of prednisone achieved complete remission off therapy by 24 months, compared with about three in ten patients on prednisone alone. The rituximab group also needed far less total prednisone over the treatment period.13PubMed Central. Efficacy and safety of rituximab in patients with pemphigus vulgaris: access to treatment and analysis of the Ritux 3 trial population
A separate head-to-head trial comparing rituximab to mycophenolate mofetil (both added to steroids) found that four times as many patients in the rituximab group achieved sustained complete remission at one year. Flares were dramatically less common: six in the rituximab group versus 44 in the mycophenolate group.14PubMed. Rituximab versus Mycophenolate Mofetil in Patients with Pemphigus Vulgaris A network meta-analysis comparing all available steroid-sparing options confirmed that rituximab was the most effective for achieving remission and reduced total steroid exposure more than any other adjuvant therapy.15PubMed. Network meta-analysis-based comparison of first-line steroid-sparing adjuvants in the treatment of pemphigus vulgaris and pemphigus foliaceus Many dermatology guidelines now recommend rituximab as a first-line option rather than reserving it for refractory cases.
Options for Refractory Disease
A minority of patients do not respond adequately to steroids, conventional immunosuppressants, or even rituximab. For these individuals, two older interventions can help. Intravenous immunoglobulin (IVIg), a pooled antibody product given by infusion, has shown benefit in refractory pemphigus vulgaris. A controlled crossover trial found that IVIg treatment significantly lowered pemphigus autoantibody levels and improved subjective disease activity scores compared with placebo infusions.16PubMed. An ‘n-of-1’ placebo-controlled crossover trial of intravenous immunoglobulin as adjuvant therapy in refractory pemphigus vulgaris
Plasmapheresis, which physically removes circulating antibodies from the blood, is another rescue strategy. Case reports describe patients who failed conventional therapy yet responded to plasmapheresis sessions, though large controlled trials of the procedure are lacking.17PubMed Central. Aggressive refractory pemphigus vulgaris that responded to plasmapheresis: a case report Both IVIg and plasmapheresis tend to be used as bridges while other therapies take hold, rather than as long-term standalone treatments.
Precision Therapies on the Horizon
The most exciting research aims to treat pemphigus vulgaris without suppressing the entire immune system. Several approaches are in clinical trials or early development. Among them, chimeric autoantibody receptor (CAAR) T-cell therapy is the most conceptually striking. The idea is to take a patient’s own T cells, engineer them to display desmoglein 3 on their surface as bait, and infuse them back. These modified T cells then seek out and destroy only the B cells that carry anti-desmoglein 3 receptors, leaving the rest of the immune system intact.18PubMed Central. Targeting therapy in pemphigus: Where are we now and where are we going? Early-stage research has demonstrated that desmoglein 3 CAAR-T cells can achieve antigen-specific B-cell depletion, confirming the precision-targeting concept in laboratory and animal models.19JCI Insight. Antigen-specific B cell depletion for precision therapy of mucosal pemphigus vulgaris
Other emerging approaches include FcRn antagonists such as efgartigimod, which work by blocking a receptor that normally recycles IgG antibodies and keeps them in circulation. By interfering with this recycling, FcRn antagonists lower the overall level of IgG antibodies in the blood, including the pathogenic autoantibodies. Bruton’s tyrosine kinase (BTK) inhibitors, BAFF inhibitors, and anti-TNF-alpha agents are also being explored.20PubMed Central. Targeting therapy in pemphigus: Where are we now and where are we going? These therapies are still at various stages of testing, and none has replaced rituximab as a standard of care yet, but the pipeline is the most active it has ever been.
Quality of Life and Oral Involvement
Because pemphigus vulgaris often hits the mouth first and hardest, its impact on daily life can be severe even when the skin appears relatively spared. Eating, drinking, and speaking become painful. A multicenter study found a significant correlation between disease severity and quality-of-life scores measured by validated oral-health and dermatology-specific tools. The presence of superficial ulcers, flaccid blisters, lesions larger than a centimeter, or more than ten lesions in the mouth were all factors that markedly worsened quality of life.21PubMed Central. Evaluation of the Quality of Life and the Demographic and Clinical Characteristics of Patients With Pemphigus With Oral Mucosal İnvolvement: A Multicenter Observational Study This is worth emphasizing because patients and physicians sometimes underestimate the disability caused by oral disease relative to visible skin blisters.
Supportive care matters alongside immunosuppressive treatment. Soft diets, topical oral anesthetics, and meticulous dental hygiene help manage symptoms. Nutritional deficiencies can develop when eating becomes too painful, so monitoring weight and dietary intake is important, particularly during flares.
Paraneoplastic Pemphigus
A distinct and more dangerous relative of pemphigus vulgaris is paraneoplastic pemphigus (PNP), which occurs in the setting of an underlying malignancy. It shares some antibody targets with pemphigus vulgaris, including desmoglein 3 (found in all PNP patients tested in one series) and desmoglein 1 (in about two-thirds), but PNP also involves antibodies against a broader set of proteins, including desmocollins.22Anais Brasileiros de Dermatologia. Paraneoplastic pemphigus: a clinical, laboratorial, and therapeutic overview Clinically, PNP tends to be more polymorphous, with a mix of blisters, lichenoid (lichen planus-like) lesions, and erosions. Oral involvement is almost universal. The most commonly associated cancers are hematologic: non-Hodgkin lymphoma, chronic lymphocytic leukemia, and Castleman disease account for the majority. In children and adolescents, Castleman disease is the most frequent association. PNP generally carries a worse prognosis than pemphigus vulgaris, partly because effective management requires treating the underlying malignancy as well as the immune-mediated blistering.
Neonatal Pemphigus Vulgaris
Pregnant patients with pemphigus vulgaris face a specific concern: maternal IgG antibodies cross the placenta freely, and anti-desmoglein 3 antibodies can transfer to the fetus. This can cause neonatal pemphigus vulgaris, in which the newborn develops blisters shortly after birth. The condition is generally transient and self-limiting, resolving as the maternal antibodies are cleared from the baby’s circulation over a matter of weeks.23CosmoDerma. A rare case of progressive neonatal pemphigus vulgaris treated successfully with intravenous immunoglobulin Severe or progressive cases are rare but have been treated successfully with IVIg. For expectant mothers with active pemphigus vulgaris, close coordination between dermatology and obstetrics helps ensure both maternal disease control and neonatal monitoring.
Pemphigus Vulgaris in Animals
Pemphigus vulgaris is not exclusive to humans. Dogs, cats, and horses all develop a form of the disease, and studying it in animals has helped researchers understand the human condition. In dogs, the disease closely resembles the human mucosal-dominant or mucocutaneous phenotype. A review of 54 canine cases found that 93% had mucosal or mucocutaneous involvement, with the lips and oral cavity affected in the vast majority. Desmoglein 3 was confirmed as the major target antigen in canine pemphigus vulgaris as well, a finding that was not documented until 2003. Cats with pemphigus vulgaris tend to develop lesions confined to the head and face, with oral cavity, lip, and nasal planum involvement being consistent features across the small number of reported cases.24PubMed Central. Deep pemphigus (pemphigus vulgaris, pemphigus vegetans and paraneoplastic pemphigus) in dogs, cats and horses: a comprehensive review The disease is rare in all species, but its natural occurrence in animals provides a valuable complement to laboratory models and reinforces that the desmoglein-targeting mechanism is conserved across mammals.