Effects of Subcutaneous Hyaluronidase Administration on Psoriatic Plaques

Dendritic cells are a key component of the inflammatory response seen in psoriasis. Several current psoriasis therapies have been shown to reduce the number of dendritic cells in patients with psoriasis, leading researchers to believe that therapies specifically targeting dendritic cells may lead to improvement in psoriasis. Research recently conducted in Dr. Gallo's lab at the University of California San Diego has shown that transgenic mice overexpressing the enzyme hyaluronidase have a significant decrease in the number of dendritic cells in the dermal component of their skin compared to wild type mice. If hyaluronidase overexpression in humans also decreases the number of dendritic cells in the dermis, then hyaluronidase therapy may improve the clinical presentation of psoriasis. In order to test this hypothesis, recombinant human hyaluronidase (Hylenex®) will be injected subcutaneously below a psoriatic plaque in human psoriasis patients every week for a total of 4 weeks. Each week the clinical appearance of the plaque will be documented. At the final visit skin biopsies of the treated plaque will be taken to visualize the histology of the plaque and look for changes in expression of different inflammatory markers.