Ultrastructural and clinical improvement in monilethrix treated with L-cystine

We report two childhood cases of monilethrix treated with L-cystine orally at a dose of 500 mg twice daily for 3 months. At the end of the treatment period clinical and ultrastructural improvements of the hair were recorded by scanning electron microscopy. An increase in hair length and a regularization of the cuticular architecture were the most significant results. Since there is no universally accepted treatment for monilethrix, several therapeutic approaches have been proposed. We suggest L-cystine as a possible choice on the basis of its known positive role during the keratinization process and its safety for treatment lasting several months.