Pemphigus herpetiformis: a case series and review of the literature

Background Pemphigus herpetiformis (PH) is a rare subtype of pemphigus that presents challenges in diagnosis. Objective To review the presentation, diagnosis, and management of PH. Methods We reviewed the charts of all patients diagnosed and treated for PH in an immunobullous referral center between September 2007 and June 2013. Results Eight patients were identified with a diagnosis of PH. All presented initially with pruritus. Clinical disease was manifest as either urticated erythematous plaques or a vesiculobullous eruption. Histological evaluation demonstrated eosinophilic spongiosis in all patients with acantholysis in half of cases (n = 4/8). Peripheral eosinophilia was noted in three of eight (37.5%) patients. In all cases, direct immunofluorescence showed intercellular deposition of immunoglobulin G in the epidermis. All patients required high‐dose corticosteroid initially. All patients treated with dapsone or sulfasalazine (n = 4) achieved at least partial control. Other effective treatments included intravenous immunoglobulin (n = 2), azathioprine (n = 2), and leflunomide (n = 1). Rituximab was ineffective in two patients. Conclusion The clinical and histological features of PH develop over time and with treatment, making distinction between pemphigus subtypes challenging and delay in diagnosis common. Diagnosis of PH requires a high index of suspicion and is made on clinical grounds (urticated erythema) in the context of compatible histology and immunofluorescence findings. Treatment may be challenging, although efficacy of sulfonamide derivatives appears to offer a therapeutic effect.