DNCB =============== From: Christopher Clay What is the current opinion regarding the safety of DNCB? Chris Clay =================== From: Gfweb@aol.com A better question is whether it does any good. I think not often. ========================= From: "L.J. Gregg" <73477.361@compuserve.com> The last I knew DNCB failed the Ames test and fell from grace, although I continue to see it mentioned on occasion. Other sources of contact allergens to use for tx by sensitization include DPC and squaric acid. I have had occasional success in already rhus sensitive individuals using oral rhus desensitization extract in 1:50 dilution once or twice a week. L.J. Gregg, MD. ===================== From: William.Liss@ncal.kaiperm.org dncb has been quite useful in my practice for recalcitrant warts, especially multiple periungual warts. =================== From: "MARK NAYLOR" On 1/23/96 Chis Clay asked: "What is the current opinion regarding the safety of DNCB?" DNCB can be shown to induce mutations in Salmonella, e.g., it is mutagenic in the Ames test. Since almost all carcinogens are mutagens, the concern is that DNCB might therefore be a carcinogen. However, as far as I am aware there are no case reports to suggest that it has ever been implicated in a human tumor, but with the current medicolegal climate you can appreciate the problem. Since DPC (diphenciprone or diphenylcyclopropenone) is not mutagenic in the Ames test, it appears to be a better tool for the immunotherapy of warts. Squaric acid dibutyl ester is also not mutagenic (I believe) but I have no experience using it. My impression is that DPC is only about 60-80% as immunogenic (potent) as DNCB in equal concentrations, but it definitely works. The only problem has been getting it, since it is not a drug, but rather a chemical, and the chemical companies do not want the legal exposure of knowingly supplying it for medical use. If availability were not such a problem, I would say that topical immunotherapy is the treatment of choice for multiple periungual warts and for many resistant types of verruca, at least in experienced hands. DPC or DNCB can be applied in high concentration in the office, or sent home in dilute concentration with the patient (be very careful who you trust to do this with, and only with much instruction). Those of you who want to know more about it that have never done could check out my old paper: 1. Naylor M, Neldner K, Yarbrough G, Rosio T, Iriondo M, Yeary J: Contact immunotherapy of resistant warts. J Amer Acad Dermatol 19(4):679-683, 1988. Mark Naylor, M.D. ========================= From: NGUZICK@eworld.com When DNCB flunked the Ames test I abandoned its use. SADBE has been quite satisfactory since then. It is a powerful immunogen and has been helpful in both recalcitrant verrucae and alopecia areata treatement. Norman D. Guzick, M.D. =========== From: KSmithDerm@aol.com DNCB for AA: Sig Muller who was until recently Chair of Dermatology at Mayo Clinic Rochester has many years of experience with DNCB and has reviewed the literature in depth. He spoke about this at the O'Leary Meeting in September and the bottom line: DNCB is very safe, and can be of great benefit when properly used in appropriate cases of alopecia areata. KC Smith, MD, FRCPC =========== From: Haines Ely DNCB, like over 150 commonly consumed food and beverages fails the Ames test. Bruce Ames has written about this many times. His take home lesson: don't worry. The risk of carcinogenesis is infintessimally small. Haines ELy ===========