Trichoscopy of Focal Alopecia in Children - New Trichoscopic Findings: Hair Bulbs Arranged Radially along Hair-Bearing Margins in Aplasia Cutis Congenita

Abstract

Purpose: To establish whether trichoscopy can be useful in the differential diagnosis of patchy alopecia in children. Procedures: The study was a retrospective analysis (2012-2015) and included 68 patients under 6 years of age. The inclusion criteria were age and the presence of 1-3 alopecia patches. A total of 124 alopecia patches were examined with the use of a videodermoscope: 102 alopecia areata, 8 tinea capitis, 6 trichotillomania, 3 temporal triangular alopecia and 5 aplasia cutis congenita. Results: In all aplasia cutis congenita lesions, trichoscopy revealed elongated hair bulbs visible through the semitranslucent epidermis, seen at the hair-bearing margin and radially arranged. Hair regrowth [upright regrowing hairs (44%), circular hairs (23%) and vellus hairs (20%)] was observed in the majority of alopecia areata patches. For triangular alopecia, upright regrowing hairs (100%; 3/3), vellus hairs (100%; 3/3) and circle hairs (33%; 1/3) were seen inside the alopecia patch. Conclusion: Trichoscopy is a useful technique for the differential diagnosis of patchy alopecia in children. A novel finding in this study indicates that radially arranged hair bulbs visible through the translucent epidermis are characteristic of nonbullous type aplasia cutis congenita.