Confluent and Reticulated Papillomatosis in Monozygotic Twins: A Case Series

Introduction: Confluent and reticulated papillomatosis (CARP) is a non-inflammatory hyperkeratotic dermatosis that commonly affects teens and young adults. While the exact pathophysiology remains unknown, multiple theories exist including familial inheritance. The present literature on genetic predisposition remains limited to intergenerational relatives and siblings. Case: We describe a case of recurrent CARP with identical presentation and clinical course in two monozygotic 16-year-old female twins. Discussion: Though familial cases of CARP have been reported, the full pathogenesis of this dermatosis remains unknown. Metabolic conditions related to insulin resistance, thyroid and pituitary derangements, and pregnancy, have also been reported in patients with CARP. Thus, there may be a gene that links CARP to the development of other endocrinologic disorders. Furthermore, the simultaneous recurrence of CARP in our monozygotic twins supports an environmental trigger theory. Thus, we hypothesize that the pathophysiology of CARP is multifactorial. Conclusion: This case confirms a strong genetic predisposition, suggesting a greater inheritance component than previously considered.