Induction of hair growth in alopecia totalis with diphencyprone sensitization

The therapeutic use of the induction of an allergic contact sensitivity to diphencyprone in alopecia areata has been studied. Fourteen subjects had alopecia totalis and four had extensive and long-standing alopecia areata. Topical diphencyprone was capable of inducing an allergic contact sensitivity in 16 subjects (89%), and 13 of these agreed to proceed to repeated intermittent applications to the left side of the scalp, the right side acting as an untreated control; six subjects achieved cosmetically useful regrowth of normally pigmented terminal hair. No clinical features seemed to distinguish those who showed a favourable response from those who did not.