Induction of hair growth in alopecia areata with D.N.C.B

43 patients with alopecia areata were treated with weekly applications of dinitrochlorobenzene (D.N.C.B.), dissolved in acetone, on one side of the head, with the other side serving as control region. The therapeutic aim was a mild contact dermatitis. A significant difference of hair growth between the treated and untreated sides was observed in 33 patients. 21 patients showed regrowth of hair exclusively on the treated side, and in 12 patients regrowth was considerably faster and more dense on the treated side. In the majority of patients the difference was noted within 3 months.