Duncan JI, Wakeel RA, Winfield AJ, Ormerod AD, Thomson AW.
DOI: 10.2340/00015555738487

Topical cyclosporin A (CyA; Sandimmun) in a formulation incorporating the penetration enhancers (PE) propylene glycol (18%) and azone (2%) was tested for efficacy in a double-blind, vehicle-controlled trial in 5 chronic plaque psoriatic patients. On each patient, two similar plaques were treated daily, under occlusion, for 4 weeks with either 8% (w/v) CyA, containing PE, or with vehicle comprising olive oil with PE. All sites improved significantly, but there was no significant difference between those receiving active and control preparations. Cryostat sections of biopsies performed after 4 weeks' treatment showed significant reductions in CyA compared with vehicle-treated sites in the number of cells, positive for CD3 and CD25 in the epidermis and CD25 and HLA-DR in the dermis. These results suggest that amounts of CyA adequate to affect the lymphocytic infiltrate penetrated the epidermis but that only partial suppression occurred in the dermis, as indicated by the reduction in lymphocyte activation status.