Diagnosis and treatment of pemphigus

Oral pemphigus vulgaris diagnostic characteristics and treatment: a systematic review

Pemphigus vulgaris (PV) is a rare, potentially fatal, immune-mediated chronic disease characterized by the presence of bullous intraepithelial lesions on mucous membranes and skin. This study aimed to perform a systematic literature review covering PV clinical and histopathological aspects and treatment. The literature searches were carried out in the Pubmed, Periódicos Capes, Scopus, Science Direct, Web of Science and Scielo databases. Articles in English or Spanish published from 2000 to 2022 comprising case reports, case series and literature reviews with case report were included. After the analyses, 21 articles were selected. PV generally presents in the third to sixth decades of life and exhibits no gender predilection. The disease manifests itself clinically through irregular and painful blisters that rupture, resulting in erosion and ulceration areas. Histopathologically, the presence of an intraepithelial cleft located above the basal layer and acantholysis are observed. Standard treatment encompasses systemic and topical corticosteroids, with prednisolone being widely employed. Management consists of a remission induction phase and a maintenance phase. An early and accurate diagnosis is paramount to quickly initiate treatment, resulting in more favorable prognoses, as the choice of treatment and responses depend on the severity of the disease. Registered at the International Prospective Register of Systematic Reviews (PROSPERO): Number CRD42024497313.

Clinical course and outcomes of pemphigus vulgaris and foliaceus: A retrospective study using a nationwide database in Japan

Pemphigus is a life-threatening autoimmune blistering disease. Patient characteristics, treatment courses, and outcomes remain unclear owing to its rarity. To describe the background, treatment, and outcomes of pemphigus, we identified 2598 patients with pemphigus vulgaris and 1186 patients with pemphigus foliaceus from a nationwide inpatient database in Japan. Patients with pemphigus vulgaris were younger (62 vs 72 years, P < 0.001), had fewer comorbidities, and were more likely to be admitted to high-volume hospitals (38% vs 30%, P < 0.001) than those with pemphigus foliaceus. Patients with pemphigus vulgaris had undergone more aggressive treatment, including steroid pulse therapy, intravenous immunoglobulin, or plasmapheresis, compared with those with pemphigus foliaceus (48% vs 42%, P = 0.001); specifically, in patients aged <70 years, the pemphigus vulgaris group was more likely to undergo aggressive treatment than the pemphigus foliaceus group (52% vs 45%), whereas there was no significant difference in patients aged ≥70 years (40% vs 40%). Immunosuppressive agents (30% vs 26%, P = 0.015) and analgesics, including opioids (45% vs 36%, P < 0.001), were used more frequently, whereas topical corticosteroids were used less frequently (32% vs 48%, P < 0.001) in patients with pemphigus vulgaris compared with those with pemphigus foliaceus. In-hospital mortality was lower in patients with pemphigus vulgaris than in those with pemphigus foliaceus (2.2% vs 4.0%, P = 0.002); in the comparison stratified by age, the mortality was equivalent among the two groups (0.6% in patients aged <70 years and 6.1% in those aged ≥70 years). Overall, patients with pemphigus vulgaris had a 10-day longer hospitalization period and higher hospitalization costs than those with pemphigus foliaceus. Our findings provide useful information for understanding the current trends in the management of pemphigus in Japan.

Pemphigus vegetans misdiagnosed as condylomata acuminata: A case report

Pemphigus vegetans is a rare variant of pemphigus vulgaris, characterized by vegetating lesions primarily in the flexures. A 41-year-old male patient presented with pemphigus vegetans highly mimicking condylomata acuminata, which led to mistreatment. Careful analysis of clinical and laboratory findings enabled us to reach a correct diagnosis and successful treatment.

A case of spontaneous autoimmune skin disease in a cynomolgus monkey (Macaca fascicularis)

Pemphigus is an autoimmune blistering disease characterized by lesions on the skin and mucous membranes. To date, no spontaneous cases of this disease have been reported in cynomolgus monkeys. This report describes the histopathological characteristics of spontaneous pemphigus in a cynomolgus monkey. Macroscopically, redness and scaling with pruritus were observed on the skin of the entire body. Histopathologically, the epidermis showed intercellular edema, and eosinophils and mononuclear cells infiltrated the epidermis. There was no obvious acantholysis in the epidermis. The perivascular area showed edema, and eosinophils and mononuclear cells infiltrated the vessels in the dermis. Immunohistochemically, the intercellular area in the epidermis was positive for Immunoglobulin G and Complement component 3. Serologically, anti-desmoglein 1 and desmoglein 3 antibodies in the serum were negative. From these findings, this case was diagnosed as an autoimmune skin disease, suspected to be pemphigus, and concluded as lesions being similar to those in human “pemphigus herpetiformis”.

State-of-the-art review of human autoimmune blistering diseases (AIBD)

Autoimmune blistering diseases (AIBDs) are a heterogenous group of skin conditions, broadly classified into two categories depending on the location of blister formation: intraepidermal blistering in the pemphigus group and subepidermal blistering in the pemphigoid group. Although AIBDs occur in both humans and animals, the arsenal of data for human AIBDs far exceeds those of their animal counterpart. Therefore, the main purpose of this review is to highlight existing knowledge, and recent advances in the diagnosis and management of AIBDs in humans - to serve as a road map for veterinary dermatologists. AREAS COVERED: Recent findings include complement-independent pathways in the pathogenesis of bullous pemphigoid, as well as the role of desmoglein and desmocollin autoantibodies in inducing acantholysis. Systemic glucocorticoids are the mainstay of treatment for AIBDs in humans, yet their long-term use is associated with severe adverse effects and complications, thereby limiting their use. Therefore, researchers have been exploring new and safer alternative therapeutic options for human AIBDs such as anti-CD20 monoclonal antibodies (Rituximab), Bruton's tyrosine kinase inhibitors (BTKi) and neonatal Fc receptor (FcRn) blockers. EXPERT OPINION: Randomised controlled trial (RCT) level evidence show that Rituximab and short-course GC regimes are more effective and safer than traditional GC treatment for human AIBDs. FcRn blockers such as SYNT001 have shown positive results in preliminary phase 2 clinical trials for treatment of human pemphigus; further trials are required. Rilzabrutinib (PRN1008), an orally administered BTKi, has recently completed phase 2 trials in pemphigus and is in a phase 3 RCT in humans.

Anti-human serum albumin autoantibody may be involved in the pathogenesis of autoimmune bullous skin diseases

Although effective immunological diagnostic systems for autoimmune bullous skin diseases (AIBD) have been established, there are still unidentified cutaneous autoantigens. The purpose of this study is to investigative whether anti-human serum albumin (HSA) autoantibodies exist in AIBD sera and their potential pathogenesis. By immunoprecipitation-immunoblotting, immunofluorescence assay, anti-HSA autoantibodies could be detected in AIBD sera; by ELISAs, positive rates of AIBD sera for IgG and IgA anti-HSA autoantibodies were 29% and 34%, respectively. The IgG anti-HSA autoantibodies in ABID sera recognized a number of HSA antigen epitopes and therefore a polyclonal antibody against HSA were next employed to study its pathogenesis. In vitro cell and tissue culture models, anti-HSA antibody could influence DNA damage-related signaling proteins, via activation of phospho-p38 signaling pathway. This is the first report that an autoantibody may influence DNA damage-related signaling proteins. Statistical analyses also proved that anti-HSA autoantibodies were positively correlated with various known autoantibodies and clinical features of ABID patients. In summary, IgG and IgA autoantibodies to HSA may have diagnosis values for AIBD. DNA damage-related signaling proteins might be involved in the pathogenic role of anti-HSA autoantibodies in AIBD. Phospho-p38 signaling pathway is a potential target for treatment of AIBD positive for serum anti-HSA autoantibodies.

Validation of the BIOCHIP test for the diagnosis of bullous pemphigoid, pemphigus vulgaris and pemphigus foliaceus

BACKGROUND

The BIOCHIP is a novel multiplex indirect immunofluorescence technique used in the serological diagnosis of bullous pemphigoid and pemphigus. The BIOCHIP method combines the screening of autoantibodies and target antigen-specific substrates in a single miniature incubation field.

OBJECTIVE

To evaluate the diagnostic accuracy of the new immunofluorescence BIOCHIP multiplex tool in pemphigus and bullous pemphigoid.

METHODS

For the validation of the BIOCHIP, sera from patients with BP (n = 38), PF (n = 8) and pemphigus vulgaris (PV) (n = 23) were used. In addition, sera from disease control patients (n = 63) and healthy volunteers (n = 39) were used. The multiplex BIOCHIP and direct immunofluorescence (DIF) were performed for all BP, PF and PV patients. Additional indirect immunofluorescence (IIF) was performed on patients with BP, and ELISA was performed on patients with pemphigus.

RESULTS

The BIOCHIP mosaic showed a sensitivity of 86.8% and specificity of 85% for BP180 or BP230 being positive in BP. It demonstrated a sensitivity of 75% and specificity of 97.7% for Dsg1 in PF. The BIOCHIP was found to have a sensitivity of 60.9% and specificity of 73.6% for Dsg3 in PV.

CONCLUSION

The BIOCHIP mosaic-based immunofluorescence test is potentially a simple, time and effort saving test that can aid in the diagnosis and screening of BP, PV and PF. However, there is potential for interpretation bias and a learning curve that needs to be taken into consideration.

Clinical and Immunological Study of 30 Cases With Both IgG and IgA Anti-Keratinocyte Cell Surface Autoantibodies Toward the Definition of Intercellular IgG/IgA Dermatosis

Several sporadic cases, in which direct and indirect immunofluorescence studies simultaneously detected IgG and IgA autoantibodies to keratinocyte cell surfaces, have been reported mainly under the name of IgG/IgA pemphigus. However, there have been no systematic studies for this condition. In this study, we collected 30 cases of this condition from our cohort of more than 5,000 autoimmune bullous disease cases, which were consulted for our diagnostic methods from other institutes, and summarized their clinical and immunological findings. Clinically, there was no male-female prevalence, mean age of disease onset was 55.6 years, and mean duration before this condition was suspected was 18 months. The patients showed clinically bullous and pustular skin lesions preferentially on the trunk and extremities, and histopathologically intraepidermal pustules and blisters with infiltration of neutrophils and eosinophils. Immunologically, ELISAs frequently detected IgG and IgA autoantibodies to both desmogleins and desmocollins. From the characteristic clinical, histopathological, and immunological features, which are considerably different from those in classical IgG types of pemphigus, we propose this disease as a new disease entity with preferential name of intercellular IgG/IgA dermatosis (IGAD). This was the largest study of IGAD to date.

Unusual Histological Evidence of Dysplasia in a Case of Oral Pemphigus Vulgaris: A Potential Diagnostic Challenge

This report describes the management of an unusual case of oral pemphigus vulgaris (PV). The patient was referred for a painful single bullous lesion together with a small proliferative area localized in the soft palate. Histology and direct immunofluorescence data were consistent for PV but disclosed unusual signs of high-grade dysplasia in the proliferative area. At surgical removal of the dysplastic area 1 week after the start of cortisone therapy there was no evidence of dysplasia. Histological signs of high-grade dysplasia in oral mucosa are often associated with concurrent or subsequent carcinoma. However, severe inflammation may induce reactive epithelial cell changes and hence mimic histologic dysplasia. Pathologic evaluation of dysplasia in an inflammatory disease like PV may be a diagnostic challenge and a careful pathological evaluation is advisable before choosing between surgical and medical approach.

Clinical and immunological studies of 49 cases of various types of intercellular IgA dermatosis and 13 cases of classical subcorneal pustular dermatosis examined at Kurume University

BACKGROUND

Intercellular IgA dermatosis (IAD) is a subset of autoimmune bullous disease exclusively with IgA antikeratinocyte cell-surface antibodies. The classification and pathogenesis of this condition are still obscure.

OBJECTIVES

To classify IAD and study its pathogenesis.

METHODS

From our cohort of 5402 cases of autoimmune bullous disease, we selected 49 cases of various types of intercellular IgA dermatosis (IAD) and 13 cases of classical subcorneal pustular dermatosis (SPD), for which sera and information were available. We studied these cases clinically and immunologically.

RESULTS

There were 17 SPD-type IAD, 12 intraepidermal neutrophilic IgA dermatosis (IEN)-type IAD, two IgA-pemphigus vegetans, four IgA-pemphigus foliaceus, six IgA-pemphigus vulgaris and eight unclassified IAD cases. There was no sex predominance, and the average age at disease onset was 45·9 years. Clinically, bullous and pustular skin lesions developed on various sites, particularly intertriginous areas. Histopathology showed intraepidermal blisters or pustules at the upper epidermis in the SPD-type and at the midepidermis in the IEN-type. Immunological studies revealed that direct immunofluorescence, indirect immunofluorescence of normal human skin and enzyme-linked immunosorbent assays (ELISAs) of recombinant proteins of desmogleins and desmocollins frequently showed positive results, although no antigens were detected in many cases. All cases of classical SPD, which showed no positive immunological results, were indistinguishable clinically and histopathologically from SPD-type IAD.

CONCLUSIONS

The present study of the largest cohort of cases of IAD showed that the major subtypes are SPD and IEN, and that the combination of indirect immunofluorescence and ELISAs of desmogleins and desmocollins, in addition to direct immunofluorescence, was useful for the diagnosis of IAD and its subtypes.

Clinical and immunological studies for 105 Japanese seropositive patients of epidermolysis bullosa acquisita examined at Kurume University

OBJECTIVES

Using our serological diagnostic criteria, we selected 105 Japanese patients with epidermolysis bullosa acquisita (EBA), an autoimmune bullous disease (AIBD) reacting with type VII collagen, from our cohort of 5063 AIBD patients.

METHODS

We examined the patients clinically and immunologically.

RESULTS

We found diversity of clinical manifestations in both cutaneous and oral mucosal lesions and a high rate of inflammatory-type EBA patients in Japan. Common treatments were systemic steroids, followed by immunosuppressives, DDS, tetracycline/minocycline and colchicine. Immunological studies revealed that indirect immunofluorescence of 1M-NaCl-split skin, immunoblotting of dermal extract, and type VII collagen ELISA were sensitive methods, with possible multiplicity of circulating autoantibodies against other basement membrane autoantigens.

CONCLUSION

The present study analyzed the largest cohort of EBA patients, confirming the scarcity of EBA (only 105 of the 5063 AIBD patients), and showed that the three serological tests are useful for the diagnosis of EBA.

Management of Pemphigus Vulgaris

INTRODUCTION

Pemphigus vulgaris (PV) is a chronic, autoimmune, vesiculobullous disease. As a result of the relative rarity of PV, published randomized controlled trials (RCTs) are limited, which makes it difficult to evaluate the efficacy of different treatment regimens in this disease. This also precludes conduct of a meta-analysis.

METHODS

English-language publications describing treatment outcomes of patients with PV were identified by searches of electronic databases through May 2015, and additionally by review of the bibliography of these publications. A total of 89 papers, which included 21 case reports, 47 case series, 8 RCTs, and 13 observational studies, were identified. The findings from these publications, including information on disease course and prognosis, medications used, treatment responses, and side effects, are summarized in the tables and text of this review.

RESULTS

Prior to availability of corticosteroid therapy, PV had a high fatality rate. Early publications from the 1970s reported high-dose, prolonged corticosteroid use and significant associated side effects. Later reports described use of corticosteroids along with steroid-sparing adjuvants, which allows a reduction in the total dose of corticosteroids and a reduction in observed mortality and morbidity. For the majority of patients in these reports, a long-term course on medications lasting about 5-10 years was observed; however, subgroups of patients requiring shorter courses or needing longer-term therapy have also been described. Early diagnosis of PV and early initiation of treatment were prognostic factors. In recent publications, commonly used initial regimens include corticosteroids in combination with mycophenolate or azathioprine; whereas, for patients with inadequate response to these regimens, adjuvants such as intravenous immunoglobulin (IVIg) or rituximab are used.

CONCLUSION

The review findings emphasize the importance of early diagnosis, early initiation of treatment, and use of steroid-sparing adjuvants to allow a reduced total dose and duration on corticosteroids. Also highlighted is the need for more RCTs.

Nail changes in female pemphigus vulgaris patients on immunosuppressive therapy

Background

Pemphigus vulgaris (PV) patients receiving immunosuppressive therapy may develop nail alterations resulting from infection, skin disorder, or drug regimen.

Objective

This study aims to describe nail changes in PV female patients receiving immunosuppressive therapy and to report the frequency of associated fungal and bacterial growth in the patients’ nails.

Methods

Twenty-five female PV patients who had at least one acquired finger or toenail abnormality and had been administered at least one immunosuppressive drug were included in the study. Nail alterations were recorded. Nail scrapings were collected from abnormal nails for fungal and bacterial examination.

Results

Positive fungal and bacterial cultures were detected in 20 (80%) of patients’ nail samples. Five patients reported nail alterations coinciding with disease onset, whereas 13 reported nail changes after administration of immunosuppressive therapy.

Limitations

Lack of a control group (patients on similar immunosuppressive medications for conditions other than PV) which would have further supported the findings demonstrated in this observational study.

Conclusion

Nail abnormalities in severe PV patients are frequently associated with fungal and bacterial growth. Immunosuppressive therapy potentially initiates such changes.

What is already known on this topic?

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Pemphigus vulgaris (PV) patients receiving immunosuppressive therapy may develop nail alterations resulting from infection, skin disorder, or drug regimen.

What does this article add to our knowledge?

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The duration of disease in severe PV appears to dictate the longevity of nail changes in patients, and immunosuppressive therapy may initiate these nail changes either alone or as a result of opportunistic bacterial and/or fungal growth affecting the nail unit. Accordingly, prompt treatment of PV utilizing a multidisciplinary approach (combined or sequential therapy) would presumably decrease the incidence of nail affection in PV patients on immunosuppressive therapy.

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Limitations of the present work include lack of a control group (patients on similar immunosuppressive medications for conditions other than PV), which would have further supported the findings demonstrated in this observational study.

Revisited diagnostics of true (acantholytic) pemphigus

True (acantholytic) pemphigus is an autoimmune disease characterized by blisters and erosions in the skin and/or mucous tunics. True (acantholytic) pemphigus can be diagnosed based on an assessment of clinical manifestations and results of cytology, histology and immunology tests. The current diagnostics methods are characterized by certain advantages and shortcomings yet none of them has 100% sensitivity and specificity. To diagnose pemphigus, a complex of studies is needed taking into consideration the body of clinical symptoms and laboratory indices.

Plakophilin 3 mediates Rap1-dependent desmosome assembly and adherens junction maturation

Desmosomal Armadillo family member Pkp3 is established as a coordinator of desmosome and adherens junction assembly and maturation through its physical and functional association with Rap1. It thus functions in a manner distinct from the closely related Pkp2.

The pathways driving desmosome and adherens junction assembly are temporally and spatially coordinated, but how they are functionally coupled is poorly understood. Here we show that the Armadillo protein plakophilin 3 (Pkp3) mediates both desmosome assembly and E-cadherin maturation through Rap1 GTPase, thus functioning in a manner distinct from the closely related plakophilin 2 (Pkp2). Whereas Pkp2 and Pkp3 share the ability to mediate the initial phase of desmoplakin (DP) accumulation at sites of cell–cell contact, they play distinct roles in later steps: Pkp3 is required for assembly of a cytoplasmic population of DP-enriched junction precursors, whereas Pkp2 is required for transfer of the precursors to the membrane. Moreover, Pkp3 forms a complex with Rap1 GTPase, promoting its activation and facilitating desmosome assembly. We show further that Pkp3 deficiency causes disruption of an E-cadherin/Rap1 complex required for adherens junction sealing. These findings reveal Pkp3 as a coordinator of desmosome and adherens junction assembly and maturation through its functional association with Rap1.

Hepatic neosporosis in a dog treated for pemphigus foliaceus

A 4-year-old, female, spayed Border Collie dog was presented for progressive lethargy, inappetence, and weakness of 4 days duration. The animal had been diagnosed with pemphigus foliaceus 3 months prior and was receiving combination immunosuppressive therapy. Serum biochemistry revealed severely elevated liver enzymes and bilirubin, and humane euthanasia was elected. Gross postmortem examination revealed a diffusely pale tan to slightly yellow, enlarged, markedly friable liver with an enhanced reticular pattern. Histologically, the hepatic changes consisted of multifocal to coalescing areas of severe vacuolar degeneration, numerous coalescing foci of hepatocellular necrosis, and myriad intra- and extracellular protozoa that reacted immunohistochemically with polyclonal antibodies to Neospora caninum, and not Toxoplasma gondii. Neosporosis in the current case is thought to be due to reactivation of latent N. caninum occurring with the administration of glucocorticoid therapy. The severe complication in the present case highlights the importance of early detection and mitigation of common infections in immunosuppressed animals.

Clinical heterogeneity and differential diagnosis of atopic dermatitis

Atopic dermatitis (AD) is a chronic or chronically relapsing skin disease that usually presents for the first time before the age of 20 years. The disease displays great clinical heterogeneity and may resemble a number of different disorders, making the correct diagnosis of AD a significant challenge for physicians. Based on the Hanifin and Rajka criteria, the authors outline the common symptoms of AD and provide an overview of the differential diagnoses to help distinguish AD from other conditions within the clinic.

Renal transplantation dramatically reduces IgA anti-beta-2-glycoprotein I antibodies in patients with endstage renal disease

IgA anti-beta-2-glycoprotein I (aB2GPI) antibodies have been related to vascular pathology in the general population and mainly in hemodialyzed patients (prevalence 33%) in whom an elevated incidence of thrombosis and mortality is found. In this paper we have studied the presence of IgA aB2GPI antibodies at pretransplant and their evolution after transplantation with a cross-sectional-based follow-up study of a cohort of 288 endstage renal disease (ESRD) patients treated with kidney transplantation. Pretransplant IgA aB2GPI levels were elevated 31.7 ± 4.2 U/mL without differences in age or type of dialysis. Patients with different etiologies of ESRD showed higher levels of IgA aB2GPI than blood donors, except the groups of non-IgA glomerular disease and systemic erythematosus lupus, whose nonsignificant differences were observed. IgA aB2GPI antibodies dropped immediately after transplantation (10.7 ± 1.0 U/mL, P < 0.0001), coinciding with a high degree of immunosuppression, and remained significantly lower than that observed in pretransplant status. Prevalence of patients with elevated antibodies was also less in transplanted patients (8.9% versus 30.4%, P < 0.0001). Among, positivity for IgA aB2GPI was higher than in patients who had received their first transplant that those were retransplanted. This finding could have important clinical implications and can suggest new therapeutic strategies in patients with IgA aB2GPI antibodies.

Epidemiology of pemphigus vulgaris in the Northeast China: a 10-year retrospective study

The aim of the present study was to evaluate the incidence, epidemiological, clinical and therapeutic features of patients with pemphigus vulgaris in China. We retrospectively investigated a total of 221 patients with pemphigus vulgaris. The parameters including age at diagnosis/onset, sex, diagnostic methods, hospitalizations, side-effects with different treatments, pemphigus vulgaris-associated diseases, the therapeutic features and duration of follow up were evaluated. The male : female ratio was 1:1.40. The incidence rate was obviously higher in two age groups, 31-40 years and 41-50 years. The mean age at onset was 44.19 ± 21.45 years. The majority of patients (56.56%) presented the mucocutaneous type. In addition, we found that various doses of corticosteroids (including the mean initial dose, maximum control dose, total dose before reducing and hospitalized total dose) exhibited statistical differences between only corticosteroids and corticosteroids-immunosuppressant groups in mild, moderate and severe pemphigus vulgaris (P < 0.05). Our survey suggested that pemphigus vulgaris most frequently occurred in the 41-50-year age group in China and the majority of patients manifested mucocutaneous lesions. Importantly, the incidence rate in females was higher than in males. The patients who needed combined immunosuppressant treatment, usually needed higher doses of corticosteroids initially, to control the disease and over the total course of treatment.

Life-threatening course of pemphigus vulgaris complicated by sepsis caused by azathioprine-induced bone marrow suppression, successfully managed with combination therapy

Severe forms of pemphigus vulgaris (PV) that are resistant to standard treatment present a life-threatening disease with a mortality of 5-10%. The treatment is usually individualized. The most popular procedures used today include intravenous applications of immunoglobulins and rituximab. Currently the common use of pulse corticosteroids, often in first-line treatment, is being neglected. This particular case documented the severity of the disease and also the need for combined and comprehensive care, in which corticosteroid pulse therapy still plays an important role.

p38 MAPK Signaling in Pemphigus: Implications for Skin Autoimmunity

p38 mitogen activated protein kinase (p38 MAPK) signaling plays a major role in the modulation of immune-mediated inflammatory responses and therefore has been linked with several autoimmune diseases. The extent of the involvement of p38 MAPK in the pathogenesis of autoimmune blistering diseases has started to emerge, but whether it pays a critical role is a matter of debate. The activity of p38 MAPK has been studied in great detail during the loss of keratinocyte cell-cell adhesions and the development of pemphigus vulgaris (PV) and pemphigus foliaceus (PF). These diseases are characterised by autoantibodies targeting desmogleins (Dsg). Whether autoantibody-antigen interactions can trigger signaling pathways (such as p38 MAPK) that are tightly linked to the secretion of inflammatory mediators which may perpetuate inflammation and tissue damage in pemphigus remains unclear. Yet, the ability of p38 MAPK inhibitors to block activation of the proapoptotic proteinase caspase-3 suggests that the induction of apoptosis may be a consequence of p38 MAPK activation during acantholysis in PV. This review discusses the current evidence for the role of p38 MAPK in the pathogenesis of pemphigus. We will also present data relating to the targeting of these cascades as a means of therapeutic intervention.