Hair in newborns and infants: clinical and dermoscopic evaluation of 45 cases

The literature still lacks comprehensive assessments on the features of neonatal hair and scalp characteristics.

To evaluate the clinical and dermoscopic features of scalp hair in newborns, including measurement of hair density, length and diameter.

Forty-five newborns were recruited for the study. For each patient, data regarding sex, age at consultation, delivery method, gestational age and maternal age at delivery were collected. A clinical score of hair density was created by investigators in order to divide the neonates into two groups: group 1 included neonates with poor and slightly poor hair density and group 2 included neonates with quite good and good hair density. Each patient underwent scalp videodermatoscopy.

Based on their clinical score, 15 newborns had good hair density, while 30 had poor hair density. Among the parameters evaluated by the investigators, only weight at birth significantly correlated with neonatal hair density. Two neonates presented a frontal-temporal pattern of hair loss. Videodermatoscopy revealed that nine neonates, all in the poor hair density group, had a particular hair shaft dermoscopic feature, characterized by the presence of widespread thin hair.

On the basis of the results obtained from our study, we propose a new classification of transient neonatal hair loss. We have found two different hair types: 'neonatal type', rarely observed, that appears in the first 4 weeks of life with a frontal-temporal pattern; and 'classic type', more frequently observed, appearing at 8-12 weeks of life with a predominant occipital pattern.