Background.

Sirolimus is an immunosuppressive drug recently developed for organ transplantation. Its mechanism of action, independent of calcineurin, is different from that of cyclosporine and tacrolimus, two calcineurin inhibitors (CIs). Because the toxicity of CIs is partly the result of calcineurin blockade, sirolimus exhibits a different toxicity profile. In this study, we evaluated the profile, frequency, and severity of cutaneous adverse events in renal transplant recipients receiving sirolimus-based therapy.

Patients and Methods.

A systematic and in-depth evaluation of skin, mucous membranes, nails, and hair was performed in 80 renal transplant recipients receiving sirolimus-based therapy. The mean duration of the graft was 6 years and of sirolimus treatment was 18 months. Mycophenolate mofetil and steroids were combined with sirolimus for 74 patients. Sirolimus was used as first immunosuppressive therapy for 36 patients, and 44 patients were switched from CIs to sirolimus.

Results.

Seventy-nine patients (99%) experienced cutaneous adverse events. Twenty patients (25%) demonstrated serious adverse events, and six patients (7%) stopped sirolimus during the 3 months after the study because of cutaneous events. The most frequent of these were pilosebaceous apparatus involvement, including acne-like eruptions (46%), scalp folliculitis (26%), and hidradenitis suppurativa (12%); edematous complaints, including chronic edemas (55%) and angioedema (15%); mucous membrane disorders, including aphthous ulceration (60%), epistaxis (60%), chronic gingivitis (20%), and chronic fissure of the lips (11%); and last, nail disorders including chronic onychopathy (74%) and periungual infections (16%).

Conclusions.

Skin disorders are frequent in renal transplant recipients receiving sirolimus as a long-term therapy. Despite the usually mild nature of skin events, they are often the reason for stopping sirolimus.