Congenital alopecia is a rare condition, nearly always temporary, in which the hair loss may be general or in circumscribed areas, may be scanty or retarded in its growth, or simply downy in character. It is usually caused by a delay in the development of the hair and may be associated with defective growth of teeth, nails and other structures. Usually the hair grows after an interval of weeks, months or years. A few cases have been reported where the condition was permanent.
Etiology and Pathology. Heredity is the only known etiological factor because the condition has been frequently observed in brothers and sisters and occasionally in their parents. Little can be learned from a pathological study, beyond the fact that defects in nutrition and development cause rudimentary growth of other cutaneous structures as well as hair-follicles.
Prognosis and Treatment. The former is poor and the latter un-satisfactory. Although most cases eventually develop a permanent growth, it is usually an apology for real hair. Treatment, when it is feasible, is the same as for alopecia prematura with an accent upon the internal administration of deep- acting constitutional remedies.