Bilateral congenital triangular alopecia in a neonate: a case report

Abstract

Introduction: Congenital triangular alopecia is a rare dermatologic disorder characterized by the presence of a well-demarcated and unilateral alopecic plaque usually located in the frontotemporal region. In this report we describe an atypical case of a newborn with bilateral and symmetrical alopecic lesions, being one of the few cases described in the neonatal age. Case presentation: Female patient, of indigenous ethnicity, with minor medical history and normal prenatal and postnatal development. Clinical findings included two well-demarcated alopecic lesions, approximately 2 cm x 2 cm in the temporoparietal region, bilaterally, with the presence of fine, clear hair at the level of the lesions and miniaturization of the hair follicles, while the underlying skin showed no atrophy or discoloration. The diagnosis was based on clinical features and trichoscopic study of the lesions. Conclusions: A definitive diagnosis of congenital triangular alopecia congenita was stated. The differential diagnosis excluded other causes of circumscribed non-scarring lesions in newborns. The prognosis is favourable, as it is a benign and non-progressive skin condition. Treatment focused on parental education and support, avoiding invasive interventions. The present report highlights the importance of early recognition and a conservative approach in the treatment of this anomaly.