• Recombinant human interferon gamma used for treatment of psoriatic arthritis was found to induce expression of HLA-DR, but not HLA-DP or HLA-DQ, on keratinocytes at the site of injection. Some patients showed an improvement of their joint symptoms, but the cutaneous manifestations remained unaffected. In 10 of 42 patients, punctiform psoriatic foci could be induced at the site of injection of interferon gamma. For this presentation, we selected a female patient with psoriatic arthropathy and type II diabetes mellitus in whom psoriasis was induced at the site of application of interferon gamma, but not after subcutaneous injection of insulin or placebo. We conclude that interferon gamma is an important lymphokine in the development of psoriasis.
(Arch Dermatol. 1990;126:351-355)