John R. Tkach, M.D.
300 North Willson, Suite 203B
Bozeman, MT 59715
(406) 587-5442

Dibutyl Squaric Acid Ester (DBSAE) (squaric acid dibutyl ester) Immunotherapy of Warts

Patient Information Sheet

Immunotherapy of warts with 1-chloro-2, 4-dintrochlorobenzine (DNCB) was invented around 1972 by Dr. Henry Lewis, my mentor. He trained me in its use. DNCB is a powerful allergen. Rubbed onto the skin, it will induce contact dermatitis within a few days to weeks. When rubbed onto warts, the allergic skin reaction, rash, signals a release of cytokines, mediators of inflammation. Lymphocytes migrate into the wart, and the wart is killed sort of as an innocent bystander of the inflammatory reaction.

However, it does not have to be DNCB. If you are already allergic to a topical agent such as nickel, neomycin, lanolin, poison ivy, poison oak. poison sumac, chromium, formaldehyde, benzocaine, rubber, or ethylenediamine, etc., that substance could be tried. If you are already allergic to something, perhaps we don't need to use DBSAE.

Are you allergic to any substances that come into contact with your skin? _______________

If yes, what have you had allergic skin rashes to? ___________________________________________

I used DNCB immunotherapy until about 1985. I never saw it fail. But I have also had good results with other topical allergens. DNCB is awkward to use. It has fallen out of favor. I do not think anyone still uses it. It has been replaced by DBSAE.

Some people do not have any topical allergies. For them, we must induce an allergy. Dibutyl squaric acid ester has replaced DNCB. The part of the immune system that is supposed to do its job and cure warts is called cell-mediated immunity. If a person is not naturally allergic to a topically applied substance, we can artificially induce a cell-mediated allergy to DBSAE.

BDSAE seems rare. It has been used in industry to make photographic emulsions more stable and as an anti-fog agent. It seems to be artificially produced. It is unlikely you will come into contact with DBSAE in daily life. Several studies concluded that DBSAE immunotherapy of warts is effective and safe (Lee & Mallory, JAAD 1999, 41: 595-599 and Ajith, J. Drugs Derm. March 2006.

This treatment is not approved by the Food and Drug Administration. It is not banned, it's just that no drug company has put out the $7 million plus needed to satisfy the FDA. Once allergic to DNCB, it cannot be undone. Sometimes allergies fade over time.

What You Will Do:

  1. Day 1: Sensitizing Dose: Let me look at you and see if you are a candidate for DBSAE immunotherapy. Topical DBSAE is available by my prescription at Rocky Mountain Pharmacy, a compounding pharmacy at Main and Mendenhall, 587-4332. We will start with 3% - 4% DBSDAE cream. I will apply the sensitizing dose to your upper leg and cover it with a band-aid. After 2 full days, remove the band-aid and thoroughly wash in the shower. Over the next 2-12 days, you should get a red rash at that site. I do not want to let the reaction advance to the point of blisters. If it gets too sore or little blisters, stop treatment, use the cortisone cream, and return to see me.
    If at anytime during the immunization phase or treatment phase, the reaction is too severe, stop using the DBSAE cream and apply the cortisone cream I gave you a prescription for. Call me and let's talk about it.
  2. Day 12: Office Visit: Return to my office for evaluation of the immunization progress. If the immunization worked, you can start using the DBSAE cream to the warts. Here's how you do it. Use a Q-Tip to apply the DBSAE cream to the wart. Apply a small amount and rub it in until the cream is absorbed into the wart. Do not get the medicine onto your fingers, other areas of skin, clothes, or furniture.
    The most convenient time to put the medicine on is bedtime. If you are applying to hands or feet, cover with white cotton socks or gloves.
    Once the application is done, put the Q-tip into an empty soda bottle or can. Do not throw Q-tips into the trash.
  3. Regular Visits: You should come back to see me every 3-4 weeks until the wart is gone.
    If the reaction is too severe, we can have the pharmacy dilute it down.

I have read this information on DBSAE immunotherapy of warts. I understand the complications and do agree to my using DBSAE immunotherapy of warts.


Date / Patient's Signature

The information provided in these patient information sheets is offered for general informational and educational purposes only; it is not offered as and does not constitute medical advice. In no way are any of the materials presented meant to be a substitute for professional medical care or attention by a qualified practitioner, nor should they be construed as such.

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