Ecthyma-gangrenosum-like bullous pemphigoid

Bullous pemphigoid (BP) is a chronic, autoimmune, subepidermal blistering skin disease with varied clinical presentations. Diagnosis is based on the clinical picture, histopathological findings, and direct and indirect immunofluorescence studies. In unclear cases, ELISA or Western blot analysis helps to establish a definite diagnosis by the detection of immunoglobulin G autoantibodies specific for the hemidesmosomal BP antigens BP230 and BP180. We report 3 cases of BP with an as yet not characterized, distinctive ecthyma-gangrenosum-like presentation. Patients were female, above 80 years of age, physically immobile, and skin lesions showed truncal localization and bacterial colonization. Factors contributing to physical immobility were a high body mass index, psychiatric disease, sedative medication and rheumatic disease. The clinical picture resembled ecthyma gangrenosum but lacked systemic infection with Pseudomonas aeruginosa. Lesional bacteriological studies revealed Staphylococcusaureus and/or P. aeruginosa. Diagnosis proved challenging in all cases. Suspicion has to be high, and repeated diagnostic procedures and additional laboratory studies may be necessary to establish a definitive diagnosis of BP. In summary, we propose this combination of truncal ecthyma-gangrenosum-like lesions with bacterial colonization in the context of older age and immobility as a clinically distinct presentation or variant of BP.