The treatment of alopecia areata with dinitrochlorobenzene

In 19 patients with alopecia areata, the therapeutic efficacy of weekly topical application of 2,4-dinitrochlorobenzene (DNCB) was compared with that of a solution of dithranol. After 15 applications, 12 patients showed regrowth of hair, which in 6 cases could be attributed to the treatment with DNCB. In the course of the treatment, some patients developed contact hypersensitivity to dithranol; in 4 of them, dithranol, also, induced hair growth. No growth of hair was seen in any of the patients in whom dithranol by itself evoked a toxic reaction only. In 9 of the 19 patients, repeated application of DNCB led to side effects, which in some cases were severe. The authors are of the opinion that the value of DNCB for the treatment of alopecia areata is questionable.