This rare form of fragility is usually confined to the hair of the scalp and is characterized by nodules along the shaft between which are narrowed portions lighter in color than the pigmented nodules. Hence a checkered appearance of the hair results. Secondary fractures occur in the internodular spaces, due to atrophic changes, whereas in trichorrthexis nodosa the seats of the fractures are at the nodes. A varying amount of alopecia results and keratosis pilaris in some degree usually complicates.
Etiology and Pathology. Both sexes are affected. The condition usually begins in infancy and it is probable that most cases are congenital. Several members of the same family often present this condition. Nervous shock and traumatisms are the most important factors in the few acquired types. Kaposi believes that the disease is due to a periodic aplasia of the hair.
Prognosis and Treatment. The outlook for a cure is poor although something may be done along hygienic and dietetic lines to improve the general condition. The existing keratosis can be relieved by weak sulphur or salicylic acid ointments. Local or general stimulation is accomplished by systematic bathing, exercise and massage. The tissue remedies are those usually indicated.