Atypical pemphigus foliaceus with pustular lesions: a case series

BACKGROUND: Pemphigus foliaceus usually presents as erosion, scales, and crusts on an erythematous base. Atypical presentations of pemphigus foliaceus, especially with pustular lesions, are exceedingly rare and pose significant diagnostic challenges. This case series highlights two cases of atypical pemphigus foliaceus with prominent pustular lesions that were encountered over 12 years. CASE PRESENTATION: We report two cases of atypical pemphigus foliaceus in an 18-year-old Sundanese female patient and a 57-year-old Javanese male patient. Both patients had clinical manifestations of prominent pustular lesions, and histopathological examination revealed neutrophilic infiltration. However, direct immunofluorescence examination showed intercellular immunoglobulin G deposits on the surface of keratinocytes, which supported the diagnosis of pemphigus foliaceus. The lesions of the first patient showed improvement following the administration of cyclophosphamide 100 mg daily. The second patient, initially treated with sulfasalazine without success, showed improvement with the combination of corticosteroid equivalent to prednisone 1 mg/kg/day, azathioprine 50 mg twice daily, and psychotherapy. CONCLUSION: Pemphigus foliaceus can occur with atypical clinical manifestations, including prominent pustular lesions with neutrophilic infiltration, resembling pustular dermatosis's clinical manifestations. However, direct immunofluorescence examination may help to differentiate atypical pemphigus foliaceus and other differential diagnoses. Given the challenges in diagnosing chronic vesiculobullous diseases with atypical presentations, clinicians should consider pemphigus foliaceus in the differential diagnosis of prominent pustular lesions to avoid misdiagnosis and ensure appropriate management.