Psoriasis can best be understood from a multifactorial approach that recognizes the systemic aspects of the disorder. Among the various factors thought to be involved in the etiology and pathogenesis of psoriasis, bowel pathology has assumed a noteworthy position in the literature. This article reviews the psoriasis/bowel connection with regard to abnormal bowel structure and physiology in psoriasis patients. Clinical implications of bowel involvement in psoriasis are discussed within the framework of an integrative medicine model that emphasizes natural therapeutics for addressing the systemic aspects of the illness.

Nine patients with severe or therapy-resistant psoriasis were treated by plasma exchanges or leukapheresis; one received both treatments in succession. None of the patients showed convincing signs of improvement. We therefore conclude that there is little evidence for the existence of a "psoriasis factor", the removal of which, it has been suggested, would explain the beneficial effects of dialysis. Nor is there anything to indicate that the removal of large numbers of leukocytes would bring about healing.

Eleven patients with severe psoriasis were treated with hemofiltration once weekly for 4 consecutive weeks. Hemofiltration is a method of extracorporeal dialysis that uses a pressure gradient, rather than passive diffusion, to remove small and medium molecular weight substances from the blood. Six of the patients had very substantial clearing of their psoriatic lesions. Five patients had little or no apparent benefit during the course of hemofiltration treatments. They subsequently had dramatic clearing, however, when previously ineffective topical therapy was resumed. No patient had worsening of his condition during the hemofiltration series, and there were no perceived adverse effects.