Case report: Managing pemphigus foliaceus using apremilast without systemic glucocorticosteroids or immunosuppressive agents.

Pemphigus foliaceus (PF) is a superficial form of pemphigus. Treatment options for PF resemble pemphigus vulgaris, including glucocorticosteroids, immunosuppressive agents and rituximab et al. These treatment approaches can effectively improve the condition but may also be accompanied by high risks of side effects. Therefore, it is crucial to find a safe and effective treatment options for patients with PF. It will not only benefit/be necessary for patients who refuse glucocorticosteroids or immunosuppressive agents treatments, but also for patients who cannot be treated with glucocorticosteroids or immunosuppressive agents. Herein, we reported a case of PF that was treated with apremilast without systemic glucocorticosteroids or immunosuppressive agents. A 54-year-old woman presented with itchy erythema and erosions on the trunk for more than 1 month. The patient applied mometasonefuroate cream without improvement for a duration of two weeks. The past history of diabetes mellitus and atrophic gastritis was reported. Physical examination revealed scattered erythematous macules and erosions on the trunk. No mucosal involvement was observed. The condition was assessed by the pemphigus disease area index and numerical rating scale, with baseline scores of 7 and 8, respectively. Histopathological examination showed acantholysis and intraepithelial blister. Direct immunofluorescence revealed the presence of IgG and Complement 3 deposition between the acanthocytes with the reticular distribution. Based on enzyme-linked immunosorbent assay results, the levels of Dsg1 and Dsg3 antibodies were 28.18 and 0.26 kU/L respectively. The diagnosis of PF was made. This patient was successfully treated with apremilast without systemic glucocorticosteroids or immunosuppressive agents. The patient has continued with apremilast 30mg once daily for maintenance and no adverse events related to apremilast such as gastrointestinal side effects were observed during the 9-month follow-up period. In conclusion, apremilast therapy without systemic glucocorticosteroids nor immunosuppressive agents might provide an effective alternative to management of mild PF without obvious side effect.

Serum interleukin-6 concentration in patients with pemphigus.

Pemphigus is a rare blistering autoimmune disease that damages the integumentary system and lowers the quality of life of patients. Interleukin-6 (IL-6) has been linked to the immunopathogenesis of pemphigus, according to recent research. Thus, the investigation purpose was to assess the function of IL-6 in the development and intensity of pemphigus disease. Between January 2022 and August 2022, a case-series study involving 26 patients with pemphigus vulgaris (PV), four patients with pemphigus foliaceus (PF), and 20 healthy volunteers was carried out at the Ho Chi Minh City Hospital of Dermato-Venereology. Patients with PV and PF had significantly higher serum IL-6 concentrations than healthy volunteers (p<0.001). Patients with a positive Nikolsky sign had significantly higher serum IL-6 concentrations than those with a negative sign (p<0.001). The serum IL-6 concentration and the pemphigus disease area index were found to significantly correlate (r=0.8, p<0.001). According to our findings, IL-6 might be a significant factor in pemphigus development and severity. Thus, novel treatments that specifically target IL-6 could be a good option for managing pemphigus, particularly in its more severe forms.

Factors associated with non-pathogenic antibodies against desmoglein-3 in pemphigus foliaceus.

BACKGROUND: Anti-desmoglein (Dsg)1 is produced in pemphigus foliaceus (PF), affecting exclusively the skin. Pemphigus vulgaris (PV) shows the production of anti-Dsg3 in the mucosal form, and anti-Dsg1 and 3 in the mucocutaneous form. Anti-Dsg3 autoantibodies have been rarely reported in PF. OBJECTIVES: To determine the factors associated with the production and pathogenicity of anti-Dsg3 in PF. METHODS: Comparative analytical study of three patients groups: 16 PF-anti-Dsg3+, and 42 PF-anti-Dsg3(-) and 22 PV treatment-naïve cases. Serum was used in the anti-Dsg1 and 3 ELISA, and in immunoblotting (IB) with human epidermis extract. The expression of Dsg1 and 3 in paraffin sections was analyzed by immunohistochemistry (IHC). HLA-DRB1 alleles were compiled from a database. RESULTS: In the PF-anti-Dsg3+ group: age range similar to that of the PV group (p > 0.9999); predominance of the generalized form of PF (p = 0.002); anti-Dsg3 titers lower than those of PV (p < 0.0001); IB confirmed Dsg3 identification in one (8.33%) of 12 patients; IHC showed exclusive cytoplasmic internalization of Dsg1; HLA-DRB1 alleles of susceptibility to PF, with the absence of alleles associated with PV, in the five typed patients. STUDY LIMITATIONS: Most of the patients in the PF-anti-Dsg3+ group were undergoing treatment. CONCLUSION: The presence of anti-Dsg3 antibodies in PF was related to older age (comparable to that of PV) and the generalized form of PF. The non-pathogenicity of anti-Dsg3 antibodies in PF can be attributed to the low serum anti-Dsg3 titers, the lack of Dsg3 internalization as detected by IHC, and the absence of PV-associated HLA-DRB1 alleles.

Comparative study of efficacy and safety: Biosimilar rituximab versus originator rituximab in the treatment of pemphigus.

Rituximab is a monoclonal antibody that targets CD20 antigen in B cells. For pemphigus, rituximab has been highly effective in steroid-sparing therapy for moderate to severe cases. Originator rituximab has demonstrated favorable treatment effects in patients with pemphigus, but its high cost remains a challenge. Biosimilar rituximab is expected to offer a potential solution. However, it is required for the comparative study of efficacy and safety between biosimilar and originator because all biosimilars may not be identical to the originator. In this study, we compared the treatment effects and safety of biosimilar (Truxima) and originator (MabThera) rituximab in patients with pemphigus. A final cohort of 52 patients in the MabThera group and 72 patients in the Truxima group was enrolled. Except for the intravenous immunoglobulin administration rate, there were no differences in baseline characteristics between the two groups, and for the purpose of comparing efficacy, investigations into time to complete remission, total steroid intake to complete remission, and total steroid intake for 6 months following rituximab treatment revealed no significant differences between the two groups. Truxima can be considered a relatively affordable alternative treatment option for pemphigus, offering cost-effectiveness to patients who are indicated for the treatment with MabThera.

Autoimmune Dermatopathies of Horses.

Autoimmune dermatopathies are not common in horses. These autoimmune diseases can be idiopathic or triggered by an antigen such as drugs, vaccines, or neoplasia. The most common one is pemphigus foliaceus, which manifests as a pustular, crusting eruption. Other more common pustular diseases should be ruled out before considering pemphigus. Vasculitis is relatively common in horses and can be triggered by a variety of antigenic stimulations. Systemic lupus and true idiopathic autoimmune vasculitis are very rare in horses. Every effort should be made to reach a final diagnosis, as the prognosis for true idiopathic autoimmune skin diseases is poor.

Diagnosis, treatment, and long-term outcomes of pediatric pemphigus: a retrospective study at tertiary medical centers.

BACKGROUND: Pediatric pemphigus is a rare bullous disease that represents a diagnostic and therapeutic challenge;  evidence on patients' response to various treatments and long-term surveillance data are lacking. We aimed to investigate pediatric pemphigus patients' characteristics, diagnosis, therapeutics, response, and long-term follow-up. METHODS: This is a retrospective study of all pemphigus patients aged <18 years, diagnosed between 2000 and 2023, from three tertiary medical centers in Israel. The diagnosis was confirmed by positive immunofluorescence. RESULTS: Twelve pediatric pemphigus patients were included (mean age 10.7 ± 4.3 years, male:female ratio 1:1). Mean diagnostic delay was 11.1 ± 12.6 months (range 1.8-36 months). Most patients had pemphigus vulgaris with mucosal involvement (58.3%). First-line treatment for all patients included systemic corticosteroids (sCS), with a treatment duration (including tapering down) of 28 ± 18.4 months. Hospitalization did not yield better outcomes. Only three patients achieved sustained complete response with sCS treatment (25.0%), and the rest required additional therapeutics, most commonly rituximab. Rituximab showed a good safety profile and therapeutic response. Follow-up was recorded up to 18.1 years after diagnosis (mean: 5.6 years). Three of five patients with information available more than 5 years after the pemphigus diagnosis still exhibited disease symptoms. CONCLUSIONS: Pediatric pemphigus is associated with a significant diagnostic delay. While sCS can induce remission in most patients as a first-line treatment, long-term disease control requires additional immunomodulators. Long-term follow-up reveals a chronic yet mostly benign disease course in this population and advocates for the use of rituximab in pediatric pemphigus patients.

New Onset and Exacerbation of Autoimmune Bullous Dermatosis Following COVID-19 Vaccination: A Systematic Review.

BACKGROUND: Cases of autoimmune bullous dermatosis (AIBD) have been reported following COVID-19 vaccination. OBJECTIVE: We aimed to provide an overview of clinical characteristics, treatments, and outcomes of AIBDs following COVID-19 vaccination. METHODS: We conducted a systematic review and searched the Embase, Cochrane Library, and Medline databases from their inception to 27 March 2024. We included all studies reporting ≥ 1 patient who developed new-onset AIBD or experienced flare of AIBD following at least one dose of any COVID-19 vaccine. RESULTS: We included 98 studies with 229 patients in the new-onset group and 216 in the flare group. Among the new-onset cases, bullous pemphigoid (BP) was the most frequently reported subtype. Notably, mRNA vaccines were commonly associated with the development of AIBD. Regarding the flare group, pemphigus was the most frequently reported subtype, with the mRNA vaccines being the predominant vaccine type. The onset of AIBD ranged from 1 to 123 days post-vaccination, with most patients displaying favorable outcomes and showing improvement or resolution from 1 week to 8 months after treatment initiation. CONCLUSIONS: Both new-onset AIBD and exacerbation of pre-existing AIBD may occur following COVID-19 vaccination. Healthcare practitioners should be alert, and post-vaccination monitoring may be essential.

Seborrheic Pemphigus: A Misunderstood Variant of Pemphigus Foliaceus.

Seborrheic pemphigus (SP) represents a localized and superficial form of pemphigus foliaceus (PF) often mistaken for other dermatological conditions such as seborrheic dermatitis (SD) due to clinical similarities. Additionally, SP may be conceptually confused with pemphigus erythematosus (PE) due to historical terminology and overlapping clinical features. We present a case study of a 38-year-old female initially diagnosed with SD but later identified as SP through detailed clinical and histopathological analysis. We discuss the challenges in accurately diagnosing SP, emphasizing the importance of distinguishing it from PE and other acantholytic dermatoses. Furthermore, we highlight the effectiveness of topical treatment in managing SP, contrary to the systemic therapy often required for PE. Our findings underscore the necessity for further research to optimize management strategies for SP and emphasize the significance of precise terminology in clinical practice and research.

Re-evaluating the prevalence of anti-desmocollin-1 IgA autoantibodies in canine pemphigus foliaceus.

Pemphigus foliaceus (PF) is an autoimmune skin disease of dogs characterized by intraepidermal pustules containing neutrophils and dissociated keratinocytes that develop in association with circulating and tissue-bound IgG autoantibodies. A subset of IgG autoantibodies in canine PF target desmocollin-1 (DSC1), a component of intercellular adhesion complexes within the epidermis. Passive transfer of IgG autoantibodies from canine PF sera to mice was previously shown to induce skin disease in the absence of infiltrating neutrophils. In attempts to identify a mechanism responsible for neutrophil recruitment, past studies evaluated the prevalence of IgA autoantibodies in canine PF sera where they were found in <20% of affected dogs. We re-evaluated the prevalence of anti-DSC1 IgA in canine PF due to concerns regarding the sensitivity of previously used methods. We hypothesized that anti-DSC1 IgA are present in most dogs with PF but have been under-detected due to competition with concurrent anti-DSC1 IgG for binding to their mutual antigenic target. Despite removing approximately 80% of IgG from patient sera using affinity chromatography, we did not detect an increase in anti-DSC1 IgA by performing indirect immunofluorescence on canine DSC1-transfected HEK293T cells. Taken together, our results do not support a role for pathogenic IgA in canine PF.

Onychoscopic Analysis of Cyclophosphamide-Induced Polydactylic Bluish-Gray Discoloration in a Case of Pemphigus Foliaceus.

Cyclophosphamide, an alkylating agent, has rarely been observed to cause a bluish discoloration of nails, an occurrence that is typically underreported. We describe the case of a middle-aged male undergoing dexamethasone-cyclophosphamide pulse therapy for pemphigus foliaceus, who exhibited bluish-gray discoloration of the nails. It is crucial to differentiate this presentation from other conditions such as nail apparatus melanoma (NAM), which may manifest in a slightly different manner. We also report the onychoscopic findings observed in this case.

Eye and lid involvement as an uncommon feature of pemphigus foliaceus in a pediatric patient.

Pemphigus foliaceus (PF) is an autoimmune blistering disorder which affects the superficial layers of the epidermis with rare mucosal involvement. We present the case of a 12-year-old girl with PF involving the eyes and eyelids. A literature review of pediatric nonendemic PF revealed another two cases with ocular manifestations. Eyelid involvement is an uncommon feature of PF that should be properly identified and treated.

Microarray Gene Expression Analysis of Lesional Skin in Canine Pemphigus Foliaceus.

Canine pemphigus foliaceus (PF) is considered the most common autoimmune skin disease in dogs; the mechanism of PF disease development is currently poorly understood. Therefore, this study aimed to characterize the molecular mechanisms and altered biological pathways in the skin lesions of canine PF patients. Using an RNA microarray on formalin-fixed, paraffin-embedded samples, we analyzed the transcriptome of canine PF lesional skin (n = 7) compared to healthy skin (n = 5). Of the 800 genes analyzed, 420 differentially expressed genes (DEGs) (p < 0.05) were found. Of those, 338 genes were significantly upregulated, including pro-inflammatory and Th17-related genes. Cell type profiling found enhancement of several cell types, such as neutrophils, T-cells, and macrophages, in PF skin compared to healthy skin. Enrichment analyses of the upregulated DEGs resulted in 78 statistically significant process networks (FDR < 0.05), including the Janus kinase signal transducer and activator of transcription (JAK-STAT) and mitogen-activated protein kinase (MAPK) signaling. In conclusion, canine PF lesional immune signature resembles previously published changes in human pemphigus skin lesions. Further studies with canine PF lesional skin using next-generation sequencing (e.g., RNA sequencing, spatial transcriptomics, etc.) and the development of canine keratinocyte/skin explant PF models are needed to elucidate the pathogenesis of this debilitating disease.

Putative pemphigus-like reaction to oral fluralaner in a dog.

A 9-month-old mixed-breed dog developed generalised pustular dermatitis, accompanied by lethargy and hyperthermia, 7 days after oral fluralaner administration. Dermatopathological and microbiological evaluations were consistent with a pustular acantholytic dermatitis. A 4-month course of immunosuppressive therapy resulted in complete remission of lesions, which did not recur after therapy was withdrawn.

Un chien croisé âgé de 9 mois a développé une dermatite pustuleuse généralisée, accompagnée de léthargie et d'hyperthermie, 7 jours après l'administration orale de fluralaner. Les évaluations dermatopathologiques et microbiologiques sont compatibles avec une dermatite acantholytique pustuleuse. Un traitement immunosuppresseur de 4 mois induit une rémission complète des lésions, qui n'ont pas récidivé après l'arrêt du traitement.

Um cão mestiço de nove meses de idade desenvolveu uma dermatite pustular generalizada, acompanhada de letargia e hipertermia, 7 dias após administração de fluralaner. As avaliações dermatohistopatológicas e microbiológicas foram consistentes com uma dermatite pustular acantolítica. Um curso de quatro meses com terapia imunossupressiva resultou em remissão completa das lesões, que não recidivaram após o fim do tratamento.

Un perro mestizo de 9 meses desarrolló dermatitis pustulosa generalizada, acompañada de letargo e hipertermia, 7 días después de la administración oral de fluralaner. Las evaluaciones dermatopatológicas y microbiológicas fueron compatibles con una dermatitis pustulosa acantolítica. Un tratamiento inmunosupresor de 4 meses dio como resultado la remisión completa de las lesiones, que no reaparecieron después de retirar el tratamiento.

A Global View of Pemphigus: Geographical Variations.

Pemphigus, an autoimmune intraepidermal bullous disease group with roughly eight distinct forms, includes pemphigus vulgaris (PV) and pemphigus foliaceus (PF) as its predominant global forms. Despite the increased utilization of global health records and reporting systems, epidemiological data remain limited and poorly categorized. Therefore, this study aimed to conduct a review to track, identify, and characterize cases of PV and PF published and categorized worldwide. A research question was formulated; studies were selected based on the inclusion criteria; and data from these publications were systematically collected, summarized, and presented using narrative descriptions. The search strategy yielded 3,212 articles, of which 95 underwent critical analysis and data extraction. Studies from 52 countries contributed to the dataset, covering various pemphigus variants. Notably, only two countries, Iran (18.87%) and South Korea (11.43%), accounted for approximately a third of the reported PV cases, while Brazil contributed 40.25% of the foliaceus variants cases documented in the literature. These findings offer valuable insights into the global distribution of pemphigus and inform future research and healthcare efforts.

Current biologics in treatment of pemphigus foliaceus: a systematic review.

Background: Pemphigus foliaceus (PF) differs from pemphigus vulgaris (PV) in that it affects only the skin and mucous membranes are not involved. Pemphigus is commonly treated with systemic corticosteroids and immunosuppressive agents (ISAs). More recently, biologics have been used. The current literature on biologic therapy often combines treatment of PF with PV, hence it is often difficult for clinicians to isolate the treatment of PF from PV. The purpose of this review was to provide information regarding the use of current biological therapy, specifically in PF. Materials and methods: A search of PubMed, Embase, and other databases was conducted using keywords pemphigus foliaceus (PF), rituximab (RTX), intravenous immunoglobulin (IVIg), and biologics. Forty-one studies were included in this review, which produced 105 patients with PF, treated with RTX, IVIg, or a combination of both. Eighty-five patients were treated with RTX, eight patients with IVIg, and 12 received both RTX and IVIg. Results: Most patients in this review had PF that was nonresponsive to conventional immunosuppressive therapies (CIST), and had significant side effects from their use. RTX treatment resulted in complete remission (CR) in 63.2%, a relapse rate of 39.5%, an infection rate of 19.7%, and a mortality rate of 3.9%. Relapse was greater in the lymphoma (LP) protocol than the rheumatoid arthritis (RA) protocol (p<0.0001). IVIg led to CR in 62.5% of patients, with no relapses or infections. Patients receiving both biologics experienced better outcomes when RTX was first administered, then followed by IVIg. Follow-up durations for patients receiving RTX, IVIg, and both were 22.1, 24.8, and 35.7 months, respectively. Discussion: In pemphigus foliaceus patients nonresponsive to conventional immunosuppressive therapy or in those with significant side effects from CIST, RTX and IVIg appear to be useful agents. Profile of clinical response, as well as relapse, infection, and mortality rates in PF patients treated with RTX were similar to those observed in PV patients. The data suggests that protocols specific for PF may produce better outcomes, less adverse effects, and improved quality of life.