FRONTAL BONE OSTEOMA AS A CHRONIC BIOMECHANICAL TRIGGER FOR EN COUP DE SABRE

Abstract

Osteomas and localized morphea are conditions that may be triggered by trauma. This report describes an early adolescent female who presented with localized craniofacial linear morphea, also known as en coup de sabre (ECDS). The lesion developed following blunt force trauma that resulted in a frontal bone osteoma and transient neurological deficits, including a generalized seizure and hemiparesis. Magnetic resonance imaging (MRI) showed no intracranial abnormalities, however, the progressive development of the sclerotic plaque suggested a possible interaction between skeletal injury and autoimmune fibrotic dysregulation. This case highlights the possibility of a Deep Koebner phenomenon in morphea, where the underlying post-traumatic osteoma likely served as a persistent stimulus for overlying cutaneous and subcutaneous fibrosis. The therapeutic challenge posed by the refractory nature of the lesion, which progressed despite treatment with systemic methotrexate, pulse corticosteroids, and targeted 308-nm excimer therapy, emphasizes the need for early and multidisciplinary management of pediatric craniofacial morphea to prevent functional and cosmetic complications.