Pemphigus foliaceus and bullous pemphigoid are 2 distinct forms of autoimmune blistering disorders with unique clinical, histologic, and immunologic features. We describe a patient with pemphigus foliaceus that converted into bullous pemphigoid, providing evidence of clinical intermolecular epitope spreading.
An 86-year-old African American man presented in 2001 with crusted lesions in his scalp and widespread erosions involving the face, back, chest, abdomen, and extremities. No intact blisters were observed; the mucous membranes were uninvolved. Histopathologic analysis revealed acantholysis and intraepidermal blister formation within the upper epidermis, consistent with pemphigus foliaceus (Figure). Direct immunofluorescence showed epithelial cell surface IgG and C3 deposits without any skin basement membrane deposition; an indirect immunofluorescence study was not performed. The patient was treated for the next 1.5 years with prednisone (up to 60 mg/d) and azathioprine (up to 150 mg twice daily) and showed clinical improvement but then was lost to follow-up.
Peterson JD, Chang AJ, Chan LS. Clinical Evidence of an Intermolecular Epitope Spreading in a Patient With Pemphigus Foliaceus Converting Into Bullous Pemphigoid. Arch Dermatol. 2007;143(2):264-276. doi:10.1001/archderm.143.2.272