Senile baldness is usually a part of the general atrophic changes incident to old age, but no exact period of life can be set as the proper time for its occurrence because years do not measure the age of tissues. Much the same causes and conditions which produce premature alopecia may operate at the senile period, although true senile baldness is seldom seen before the fortieth year. Usually affecting the scalp it often begins at the vertex and spreads forward and backward until the whole crown is symmetrically affected; it may appear as a general thinning of the whole scalp; again, it may begin at the brow as in premature alopecia and show its advance by a receding forehead. The hair on the posterior and lateral regions is often retained, owing to the greater thickness of the scalp at these parts and its more constant exposure to light and air. To some extent these facts account for the greater freedom women enjoy from baldness at all ages. Grayness usually accompanies the condition but it may precede it.
Etiology and Pathology. An associated seborrhea is nearly as common in this condition as in premature alopecia but any underlying factors which hasten general atrophy contribute to cause senile alopecia. The pathological effect of atrophy of the skin and subcutaneous tissues is to interfered with the vascular supply of the hair-follicles, thus causing a loss of their power of production.
Prognosis and Treatment. The former is absolutely bad after the atrophic stage occurs. The thin and adherent scalp with other tissue losses, such as the teeth, vision and hearing, are all negative points although the same measures of treatment, external and internal, as are employed in alopecia prematura may postpone the inevitable.