Background: Bullous morphea is a rare disease. Its pathogenesis is unknown.
Objective: We evaluated bullous morphea clinically, pathologically, and immunopathologically and investigated the role of spirochetes and eosinophils in its pathogenesis.
Methods: The clinical and pathologic findings from 13 patients with bullous morphea were reviewed. Tissue sections were studied with the Elias-Bosma stain for spirochetes and indirect immunofluorescence for eosinophil granule major basic protein.
Results: Bullae were found in all forms of morphea; the lower extremities were the most common sites of involvement. Lymphatic dilatation was found in 77% of the patients. Deposition of major basic protein was found in 60% of cases studied. There was no evidence of spirochetes in any of the specimens examined with the Elias-Bosma stain.
Conclusion: Our results suggest that the pathogenesis of bullous morphea is related to lymphatic dilatation as well as release of major basic protein from eosinophils in some patients. We found no association between spirochetes and bullous morphea.