In connection with the rapid improvement noticeable during the past summer, I may refer to one or two circumstances which may have been purely incidental, but which I am inclined to believe exercised an important influence upon the renewed growth of the hair.
In June last the patient suffered from a severe attack of measles, the immediate effect of which was the complete loss of the existing hair upon the vertex, but which was speedily followed by a growth much more abundant and vigorous than before in this region, and also by signs of renewed activity on the part of the follicular structures of the temporal and occipital regions, as well as those of the eyebrows and eyelids.
What influence this intercurrent attack of measles may have had in energizing the hair's growth or the rationale of such action cannot be clearly explained. We know that the pathological changes in measles are distinctly grouped about the blood-vessels and follicular structures of the skin, and it is possible that the congestive stimulus thus exerted may have awakened into activity the long dormant trophic influence which presides over the pilary structures.
J Cutan Genito-Urin Dis.
Morrow PA. THE TREATMENT OF ALOPECIA AREATA-WITH CASES. Arch Dermatol. 1991;127(10):1491. doi:10.1001/archderm.1991.01680090055005