Prevention of UV-induced Carcinogenic Skin Alterations in Immunosuppressed Solid Organ Transplanted Patients

Inclusion Criteria: * Out-Patients of either sex aged ≥ 40 years * Life-expectancy of 2 years at minimum * Solid organ-transplant recipients who received a kidney (including pancreas), liver, lung, or heart transplant * Patients treated for 5 years with an immunosuppressant medication * Severe sun damage of the skin * Multiple actinic keratoses (2-5 lesions) and/or multiple dysplastic naevi * No present squamous cell carcinoma, basal cell carcinoma or malignant melanoma; but history of cutaneous/cutaneous invasive malignancy with restitutio ad integrum is allowed * Patients who are able to understand and provide written informed consent to participate in the clinical trial (signed informed consent) according to ICH GCP Exclusion Criteria: * Non-Caucasian * Absence of sun damage i.e. no signs of AK * Multi-organ transplantation (exception: simultaneous transplantation of kidney and pancreas) * Evidence of systemic infection, except viral hepatitis, at the time of recruitment * Known or supposed systemic malignant tumour or systemic chemotherapy within the last 5 years prior to randomisation * Patients participating in a clinical trial within the last four weeks before trial * Patients treated with the antitumour/antiangiogenetic immunosuppressant sirolimus, respectively everolimus, or acitretin or any other systemic treatment for AK at the time of randomisation * Patients treated with a topical drug for the AK at the time of randomisation (exception: excision or Cryotherapy for hyperkeratotic lesions are allowed) * Change of the immunosuppression-treatment less than 3 months ago or planned * Present or planned interferon therapy (in liver transplant patients with hepatitis B/C) * Female patients with childbearing potential with a positive pregnancy test, breast feeding, or female patients with childbearing potential without adequate contraception