2,4-Dinitrochlorobenzene Therapy for Plantar Warts

To the Editor.—  Dr. Henry Lewis suggested the use of 2,4-dinitrochlorobenzene (DNCB) as therapy for plantar warts at the American Academy of Dermatology meeting in December 1972. Further efficacy of this therapy was reported by Greenberg et al in 1973.¹ We suggested the therapy was working immunologically to enable the body to recognize the foreign virus. This therapy may find wide acceptance because of an abstract in Family Circle² and a recent article by Dr. Lewis,³ who proposes large-scale exploration of this therapy.There are possible drawbacks to this treatment. According to H. Maibach, MD (oral communication, December 1973), autoeczematization is not rare. Fisher states: it has been shown that 40% of chloramphenicol sensitive subjects also reacted to 1-2-4 chlorodinitrobenzene. This makes it likely that human beings deliberately sensitized to chlorodinitrobenzene would react to chloramphenicol if this drug were administered systematically.⁴In his most recent edition,