Adult-onset Henoch-Schonlein purpura (HSP) tends to become chronic-relapsing, yet rarely leads to organ impairment, e.g. due to chronic glomerulonephritis. Bed rest, compression and nonsteroidal anti-inflammatory drugs are usually sufficient to control the active phases. We report 2 cases of adult HSP with an unusually severe evolution. One patient required intensive-care treatment for hypovolemic shock caused by hemorrhagic pancolitis; the other had progressive and extremely extensive vasculitic leg ulcers. Both were refractory to common immunosuppression with systemic corticosteroids (oral and pulse) and additive steroid-sparing immunosuppressive drugs. Only after the introduction of plasmapheresis did both patients show a dramatic improvement in the disease, with rapid and almost complete healing. Plasmapheresis is a rarely used therapeutic tool in the treatment of severe HSP, but the growing literature on its highly beneficial effect underlines its potential usefulness.