Abstract: 【Abstract】 Objective To investigate clinical features of hair collar sign in children and their implications. Methods Children with confirmed hair collar signs were collected from Department of Dermatology, Children′s Hospital of Chongqing Medical University between January 2014 and December 2017. The morphology, distribution and quantity of skin lesions and auxiliary examination results were analyzed retrospectively in 15 patients with complete clinical records. Results The center of skin lesions manifested as a round cystic lesion or a slightly depressed atrophic patch or plaque with lack of hair on the surface of the lesions. The lesions were surrounded by thick and long hair in 13 patients. The skin lesions occurred on the parietal lobe in 9 patients, and on occipital or temporal region in other patients. Of the 15 patients, 14 had solitary lesions, and 1 had multiple lesions. Six patients were complicated by nevus flammeus. Brain magnetic resonance imaging examination of 11 patients revealed abnormalities in 2, including 1 with potential skull defect and brain tissue bulging, and 1 with cystic changes on the outer side of the cranial plate. B-mode ultrasound of the brain was performed in 4 patients, and no abnormality was found. Conclusions The skin lesions of hair collar sign are various, and most are solitary lesions. It mostly occurs on the parietal lobe, and is often complicated by nevus flammeus. This sign may suggest the presence of central nervous system malformation in patients.

Key words: Hair diseases, Skin manifestations, Hair collar sign