Clinical study of porokeratosis associated with immunosuppressive therapy in renal transplant recipients

Background: The etiology of porokeratosis (PK) remains unknown, but immunosuppression is known to be a factor in the pathogenesis of PK and it may also exacerbate PK. Objective: The aim of this study was to examine the clinical characteristics of PK associated with immunosuppressive therapy in renal transplant recipients. Methods: A total of 9 renal transplant patients diagnosed with biopsy-proven PK from January 2001 to December 2006 were enrolled. The authors analyzed the patient and medication histories, clinical characteristics, and associated diseases. Results: The ages of the 9 patients ranged from 38 to 67 years (mean 52 years). All received multi-drug regimens comprised of two or three immunosuppressive agents (steroids, cyclosporine, mycophenolate mofetil, azathioprine and/or tacrolimus). Times between transplantation and the onset of PK ranged from 2 to 9 years (mean 4.1 years). No family history of PK or a history of intense sun-exposure was elicited. The number of the lesions was less than ten in 8 of the 9. Lesions were mainly located in the extremities, though some affected the trunk or neck (3). Three patients had disseminated superficial actinic PK (DSAP), PK Mibelli, or both types. Associated diseases included verruca (4), recurrent herpes simplex (1), actinic keratosis (1), and cutaneous B cell lymphoma (1). Conclusion: The three clinical patterns of PK occurred equally in our patients, namely, coexistent PK Mibelli and DSAP, or the DSAP and Mibelli types as independent forms. Our findings support the notion that the different variants of PK be viewed as parts of a heterogeneous clinical spectrum. Further studies are needed in order to establish the clinical patterns of PK in immunosuppressed patients.