Pemphigus herpetiformis: a single-center tertiary care experience

Background/aim: Pemphigus herpetiformis (PH) is a rare variant of pemphigus with a complex pathogenesis that is often difficult to diagnose. The literature generally presents data based on small case series. This study aims to broaden the understanding of PH by presenting our cases' clinical, histopathological, and immunological characteristics. Materials and methods: A retrospective analysis of the medical charts of patients diagnosed with PH between 2008 and 2023 from the Dermatology Clinic at Atat & uuml;rk University's Faculty of Medicine was performed. The diagnostic criteria proposed by Kasperkiewics et al. were applied. All patients had lesional and perilesional skin biopsies for histopathologic examination and direct immunofluorescence microscopy. Circulating autoantibodies were detected by ELISA. Results: Four patients with a diagnosis of PH were observed. The ratio of women to men was 3:1, and the average age of the patients was 59.25 years. Pruritus was present in all patients. The oral mucosa and the scalp were affected in one and two cases, respectively. One patient showed concurrent C3 deposits at the basement membrane zone and intercellular IgG deposits on direct immunofluorescence microscopy. Peripheral eosinophilia was found in 50% of the patients. Dapsone monotherapy led to complete remission in only one patient. At least partial remission was achieved in three patients with systemic steroids +/- azathioprine. No concomitant malignant disease was detected. Conclusion: Establishing a diagnosis of PH may be delayed and requires a high level of clinical suspicion. Unusual direct immunofluorescence findings suggest a complex pathogenesis. A long but less severe disease course can be expected, even if dapsone monotherapy does not result in a satisfactory result in every patient.