Erythema Gyratum Repens: An Extensive Overview of Pathophysiology, Diagnosis, and Associations

Abstract Background: Erythema gyratum repens (EGR) is a rare dermatological disorder, characterized by severe pruritus localized to the neck and trunk, followed by the appearance of erythematous lesions in a distinctive serpiginous pattern. Purpose: The purpose of this systematic review is to comprehensively analyze and summarize the clinical features of EGR based on existing case reports. Methods: A systematic review was conducted examining the case reports of EGR. Extracted data included demographics, clinical manifestations, associated conditions, therapeutic interventions, and patient outcomes. Seventeen articles comprising 19 case reports met the inclusion criteria and were analyzed. Results: Among 19 EGR cases, 57.9% were male, with a mean age of 63 years. Malignancy was present in 42.1% of cases. Nonneoplastic associations (57.8%) included pityriasis rubra pilaris (PRP), psoriasis, an insect bite, and SARS-CoV-2 infection. Histopathology (performed in 6 cases) revealed nonspecific inflammatory changes. Five patients had persistent lesions and five died with unresolved EGR. Conclusion: This systematic review confirms the strong but nonuniversal association with malignancy. In addition, emerging associations with PRP, SARS-CoV-2, and insect bites reinforce the need for a broader differential diagnosis, pointing EGR out as a possible dermatological manifestation of immune dysregulation.