Scalp Involvement In Pemphigus: A Retrospective Cohort Study Of Clinical And Immunopathologic Features

Introduction: Pemphigus is a rare autoimmune blistering disease characterized by the presence of au-toantibodies against desmogleins, leading to skin and mucosal blisters and erosions. Scalp involvement is common but poorly characterized. Objectives: This study investigated the prevalence, clinical patterns, immunopathological features, and correlations with disease severity and serological markers of scalp involvement. Methods: A retrospective cohort study was conducted at the Dermatology Department, Fondazione IRCCS Policlinico San Matteo, Pavia, including patients diagnosed with pemphigus from 2012 to 2024. Scalp involvement was assessed through clinical examination and pull test. Data collected included demographics, disease subtype, anti-desmoglein antibody titers, PDAI scores, treatments, and outcomes. Results: Among 115 patients, 57.4% had scalp involvement. Male sex was significantly associated with scalp lesions (P=0.0148). Patients with scalp involvement had higher anti-Dsg1 titers (mean 206.4 vs. 74.2 IU/mL, P<0.001) and higher PDAI scores (mean 43.9 vs. 32.1, P=0.006). Disease severity stratification also differed significantly between groups (P=0.0147). Three clinical phenotypes were identified: scaling without alopecia, crusting and erosions (further stratified into circumscribed and confluent forms), and extensive patchy alopecia, each associated with specific clinical and serological characteristics. Conclusions: Scalp involvement is common in pemphigus and correlates with higher anti-Dsg1 titers and disease severity. Recognizing distinct scalp phenotypes may support earlier diagnosis and more targeted management.