Clinical and Trichoscopy Features in Trichorhinophalangeal Syndrome: A Multicenter Retrospective Study.

Abstract

Introduction: Trichorhinophalangeal syndrome (TRPS) is a rare autosomal dominant genetic disorder characterized by trichological, craniofacial, and skeletal abnormalities. To date, limited data are available on hair involvement in TRPS, especially those focusing on trichoscopy.

Objective: We aimed to describe the epidemiology and the clinical and trichoscopy features of TRPS.

Methods: We performed a retrospective multicenter study using chart review and images from six patients with a confirmed diagnosis of TRPS. Hair density (hair/field; field 13×1.4 mm) was classified as high (>30), medium (21-30), low (11-20), very low (5-10), or hairless (<4). The distance between follicular units, ranging from 1.0 mm to 1.4 mm, was considered normal.

Results: Most patients were females, with a median age of 12 at diagnosis. Hair density ranged from very low to medium. All female patients presented a high occipital hairline. Our patients had exclusively non-terminal hairs and no case with high hair density, following the literature, which describes thin and sparse hairs. Hair density was related to a higher proportion of single hair units, while the distance between follicles was within normal limits.

Conclusion: TRPS is notably uncommon, with hair alterations being important for diagnosis, where trichoscopy serves as a valuable tool. Our study found a normal hair diameter relationship (frontal ≥ occipital) in females, while the male patient exhibited frontal-occipital inversion. Low hair density may result from an increased number of single hair units rather than from follicular distance. The high occipital hairline is proposed as a diagnostic pearl, warranting further studies to validate our findings.