Pemphigus herpetiformis: association with malignancies and therapeutic challenges.

This case series examines the histopathological, immunological, and therapeutic characteristics of 7 patients diagnosed with pemphigus herpetiformis (PH) at a tertiary hospital between 1989 and 2025. The most common clinical manifestation was pruritic annular lesions. Direct immunofluorescence was positive in all cases, whereas serological testing (enzyme-linked immunosorbent assay, indirect immunofluorescence, and immunoblotting) performed at 2 independent referral centers detected anti-desmoglein 1 antibodies in only 2 patients, with negative antigen-specific results in the remaining patients. An association between PH and malignancy was observed in 43% of cases, particularly with lung cancer, including the first reported case of PH associated with pancreatic cancer. These findings underscore the importance of recognizing this potential association to optimize patient management. Regarding treatment, conventional therapies such as corticosteroids and dapsone showed variable efficacy, whereas rituximab appeared less effective than in other pemphigus variants.