Monilethrix: Beaded Hair and Hypotrichosis in a Child

A 9-year-old girl presented with monilethrix, a rare hereditary hair shaft disorder characterized by beaded hair and hypotrichosis, particularly at the occiput. Examination showed short, sparse, lustreless hair with follicular keratotic papules. Light microscopy revealed fusiform nodes and atrophic internodes, typical of monilethrix, which is usually autosomal dominant due to mutations in type-II hair keratin genes on chromosome 12. The condition should be distinguished from pseudomonilethrix, which lacks uniform beading and is often due to external factors. Management is supportive, with treatments like topical minoxidil, oral acitretin, and biotin showing inconsistent results.