Eruptive Disseminated Superficial Porokeratosis and Multiple Dermatofibromas in a Patient with Systemic Lupus Erythematosus under Belimumab Therapy: A Case Report

Introduction: There have been several reports on non-actinic disseminated superficial porokeratosis in association with autoimmune diseases, malignant disorders, or immunosuppressive/immunomodulatory therapies. Case Presentation: A 36-year-old female with systemic lupus erythematosus developed eruptive disseminated superficial porokeratosis on the lower legs, which appeared and increased in number after belimumab therapy was started. Physical examination showed 40 brownish superficial round plaques with slightly elevated borders on the bilateral lower legs. Histopathology revealed a narrow stack of parakeratotic corneocytes (cornoid lamella), compatible with porokeratosis. In addition, a total of 6 brownish, firm dermal nodules were observed on the thigh and lower back, which appeared a few years after the development of porokeratosis. Histopathological examination revealed dermatofibroma. Conclusion: To the best of our knowledge, there have been no reports of multiple porokeratosis under belimumab therapy. Biologic therapy may be associated with epigenetic changes in the candidate gene variation.