The hair loss in a young woman with an obscure diffuse alopecia was traced to her chronic ingestion of mouthwashes containing boric acid. Cessation of this occult source of boric acid resulted in complete regrowth of hair.
It appears that boric acid may have accumulated in the hair follicles, with a resultant toxic effect on the susceptible hair bulbs.
This case indicates that boric acid poisoning should be suspected in patients with profuse unexplained alopecia, since cessation of the boric acid ingestion results in complete hair regrowth and may be lifesaving.
Stein KM, Odom RB, Justice GR, Martin GC. Toxic Alopecia From Ingestion of Boric Acid. Arch Dermatol. 1973;108(1):95-97. doi:10.1001/archderm.1973.01620220057014