Supplementary Material for: Trichonodosis: a case report and literature review

Introduction: Hair shaft disorders include congenital or acquired conditions characterized by structural abnormalities of the hair. Trichonodosis, or knotted hair, is a rare disorder characterized by the presence of knots along the hair shaft. It can occur spontaneously or be induced by mechanical forces.

Case Presentation: An 8-year-old girl presented with short, fine, curly hair since birth. Physical examination revealed diffusely curly scalp hair with visible breakage. Trichoscopy and light microscopy showed knotted hair segments, cortical fractures, and variation in hair shaft thickness. A diagnosis of spontaneous trichonodosis was made. Treatment with topical minoxidil and gentle hair care led to improved hair length and strength over 2 years.

Conclusion: We propose that spontaneous trichonodosis with congenital onset and no mechanical triggers suggests a genetic predisposition. Although treatment options are limited, topical minoxidil may provide therapeutic benefit.