Concominant bullous pemphigoid and cutaneous Crohn disease

We report a case of new-onset bullous pemphigoid manifesting concurrently with cutaneous Crohn disease in a 58-year-old woman. Cutaneous Crohn disease is an extraintestinal manifestation of Crohn disease characterized by non-specific plaques or nodules. Bullous pemphigoid, a sub-epidermal autoimmune blistering disorder, has been observed in the setting of inflammatory bowel disease. The patient presented with recurrent bullae on the abdomen, thighs, and buttocks of 1 year's duration. She was not on any immunosuppressive therapies and had been treated with infliximab and azathioprine for her Crohn disease, which were discontinued 8 years before the blistering commenced. Punch biopsy of lesional skin showed a sub-epidermal blister with eosinophils. Sarcoidal and tuberculoid granulomas were present in the dermis. Direct immunofluorescence revealed linear 2+ IgG and 3+ C3 along the basement membrane. Indirect immunofluorescence was positive for BP180 and BP230 antibodies. These findings support the diagnosis of bullous pemphigoid with concomitant cutaneous Crohn disease. Both bullous pemphigoid and Crohn disease have been associated with an altered T-cell response. The similarities in the pathogenesis of the underlying inflammatory milieu suggest a possible etiopathogenic connection. This is believed to be the first report of cutaneous Crohn disease presenting simultaneously with bullous pemphigoid on histopathological examination.