Topical Cyclosporine and Contact Dermatitis in Guinea Pig and Man

To the Editor.—  A recent article in the Archives showed that topical cyclosporine applied to the test site of guinea pigs previously sensitized with 2,4-dinitrochlorobenzene (DNCB) inhibits the elicitation reaction of contact sensitivity.¹ Similar reports showing that topical cyclosporine is capable of inhibiting allergic and/or irritant contact sensitivity reactions in guinea pigs^2,3 have suggested the use of topical cyclosporine in patients with contact allergy. In a recent report, topical cyclosporine showed some inhibitory effect in patch test reactions to nickel in patients with nickel contact dermatitis.⁴To study whether topical cyclosporine has an effect in human DNCB-induced contact hypersensitivity, we applied topical cyclosporine in eight separate rechallenge experiments to test sites on three male volunteer subjects who had been previously sensitized with 600 μg of DNCB in a 60-μL Finn chamber. Pretreatment with topical cyclosporine on a tape-stripped skin area used for rechallenge was also studied. For