Supplementary Material for: Coexistence of Monilethrix and Androgenetic Alopecia: A Case Report and Review of the Literature

Introduction: Classic monilethrix is an autosomal dominant hair shaft disorder caused by heterozygous mutations in hair keratin genes, leading to childhood onset hair fragility and perifollicular hyperkeratosis, most prominent on the occipital scalp. Case presentation: A 38-year-old woman with lifelong occipital hair fragility and inability to grow hair beyond short lengths presented with progressive frontal scalp thinning. Trichoscopy revealed hair shaft variability of numerous hair shafts, including miniaturized hairs showing alternating nodes and internodes consistent with monilethrix and androgenetic alopecia. Conclusion: This clinical case and review of the literature underlines that diagnosis and management of monilethrix can be more difficult when it is associated with other acquired hair conditions, such as androgenetic alopecia.