We report a 3-year-old Chinese girl who presented with 
an 18-month history of a localized asymptomatic triangular area 
of hair loss in the right frontotemporal area. There was no history 
of trauma. The parents were non consanguinous and there was no 
family history of a similar lesion. Her 42-year-old father had 
androgenic alopecia that was first noted 3 years ago. Physical 
examination revealed a patch of alopecia 3.5 x 4 cm over the right 
frontotemporal area, with its apex towards the vertex. The 
overlying skin was otherwise normal. In particular, there was no 
scaling, scarring, erythema, or induration in the alopecic area. 
Dermoscopy showed normal follicular openings with thin vellus 
hairs over the affected area and terminal hairs in the adjacent 
scalp. Based on the characteristic history and physical findings, a 
diagnosis of congenital triangular alopecia was made. Awareness 
of this condition is important so that it will not be overlooked or 
misdiagnosed.