Immunofluorescence study in purpura pigmentosa chronica

Purpura pigmentosa chronica comprises a group of vascular disorders of unknown etiology. In biopsied specimens obtained from 8 patients, we observed vascular changes such as fibrinoid degeneration and occlusive damage occasioned by a hyalinized substance as well as swollen endothelia in 3. However, in all biopsied specimens, direct immunofluorescence studies demonstrated depositions of C3 or C1q with or without immunoglobulins, and of fibrin in papillary vessels. These findings suggest the possibility that immunological processes are involved in producing the histopathologic features of this disorder.