Dermal angiopathy in hemodialysis patients: the effect of time.

We studied skin biopsies from 14 patients after 6 months to 18 years on hemodialysis (HD) to discern any effect of duration of treatment on skin and dermal capillaries. Patients selected for biopsy were without evidence of other diseases known to affect vasculature such as diabetes mellitus. Pathological changes compared with duration of HD were: capillary wall thickening, endothelial proliferation and new capillary formation, lipid content, and epidermal atrophy. Severity of morphologic changes were graded from 0 to 4+ by a pathologist who had no knowledge of HD duration. The earliest change observed was reduplication of the capillary basement membrane. Narrowing of capillary lumina due to endothelial cell proliferation and new capillary formation were noted after five years of HD; lipid droplets were noted in capillaries by five years; and epidermal atrophy by 10 years. Progressive severity of each finding was associated with length of time on HD. Neither amyloid nor Ca++ deposits were observed in any specimens. By clinical observation, easy bruisability and increased skin fragility were worse the longer the patient was on HD. Capillary occlusion inducing tissue ischemia could be a cause of the atrophic skin changes noted. However, no patient manifested dermal necrosis. While pathogenesis of the capillary changes in uremic skin is unknown, the changes have been shown to stabilize following successful kidney transplantation.