Cutaneous viral infections in organ transplant patients.

Cutaneous infections might occur in up to 80% of organ transplant recipients (OTR) and viral infections are the most common them. The risk of different skin infection is among related to the intensity of immunosuppression. During the first post-transplant period, herpes viruses are most common. After some months following transplantation, human papilloma viruses represent the most significant infections among OTR. Reactivation of herpes simplex virus in OTR can become more invasive, takes longer to heal, and shows greater potential for dissemination to visceral organs compared to the general population. Specific immunosuppressive drugs (namely muromonab and mycophenolate mofetil) have been associated with an increased risk of herpes virus reactivation after transplantation. On the other hand, there is evidence that the mTOR inhibitors, such as everolimus, may be associated with a decreased incidence of herpesvirus infections in transplant recipients. The incidence of herpes zoster in OTR is 10 to 100 fold higher than the general population, ranging from 1% to 12%. The chronic immunosuppression performed in OTR may lead to persistent replication of herpesviruses, dissemination of the virus with multivisceral involvement (hepatitis, pneumonitis, myocarditis, encephalitis and disseminated intravascular coagulation) and eventually, the emergence of antiviral-drug resistance. Viral warts are the most common cutaneous infection occurring in OTR. The number of warts increases with the duration of immunosuppressive therapy. Since warts in organ recipients are frequently multiple and only rarely undergo spontaneous regression, the therapeutic management of warts in patients treated with immunosuppressive drugs might be challenging. Imiquimod, 1% cidofovir ointment, acitretin proved to be useful off-label strategies for recalcitrant cutaneous viral warts in OTR. Extensive and atypical presentation of molluscum contagiosum has been also reported in OTR, with a prevalence between 3% to 6.9%. Giant molluscum contagiosum is a clinical variant in which large nodule greater than 0.5-1 cm in diameter are observed.