Dinitrochlorobenzene (DNCB) is an organic compound used in colour photography. It comes in crystal form or pre-dissolved in solvent. In the early 1970s it was discovered that applying DNCB to verrucae (wart virus lesions) caused them to heal. In 1984 researchers found that DNCB applied to the skin of the shoulders resulted in improvement in warts elsewhere in the body in three-quarters of affected people. As well as this apparent antiviral effect, DNCB may help to correct auto-immune problems such as alopecia (hair loss) and seems to have some anti-tumour effects when applied to skin cancers.

One theory suggests that when first applied, DNCB is absorbed through the skin and, after binding to a protein, is eventually presented to CD4 lymphocytes in the lymph nodes. This is thought to activate CD4 cells causing an immune reaction at the initial site of application. Subsequent applications are thought to activate memory T-lymphocytes which in turn activate cellular immune responses throughout the body, such as CD8 (cytotoxic) T-lymphocytes.

The full chemical name of DNCB is 1-chloro-2,4-dinitrobenzene.

Current use

DNCB is an unlicensed, experimental treatment. It has been a relatively popular `underground' treatment for many years.

A small open study in people with HIV in San Francisco suggested that DNCB improved T-cell function and resulted in improvements in KS lesions. There are anecdotal reports that it may also be an effective treatment for molluscum contagiosum.

Two recent uncontrolled studies report benefits. In one, individuals were followed for six months, in the other, for an average of 24 months. In the first study the mean fall in viral load recorded was slightly less than 1 log - from 150,000 copies to 17,000 copies, and all participants experienced a reduction of at least 0.5 log. There were no statistically significant changes in CD4 or CD8 counts in this study.

In the second study participants with CD4 counts between 100 and 600 were followed for at least 24 months. None experienced a decline in CD4 counts, but not all experienced an increase in CD4 count either. CD8 counts did increase, and participants reported weight gain.

The weakness of both these studies is that the effects of DNCB alone have not been compared with another treatment, so it is difficult to judge how significant these improvements are in comparison with anti-viral treatment or other methods of modulating cellular immunity. A recent Brazilian study (Traub 1997) showed that DNCB therapy was associated with significant increases in CD4 levels. The study compared 35 people on therapy for 19 months with 6 people who declined treatment after the first application of DNCB. The reliability of this data is undermined by the small number of people in the control arm and the fact that this was not a randomised, controlled trial.

DNCB can cause quite painful itchy lesions or burns to the skin. There has been one report of a serious allergic skin reaction to the substance which resulted in total body blistering and subsequent blood infection which required prolonged hospitalisation. DNCB should only ever be used topically (externally) and not internally.

Using it

DNCB dissolved in solvent is usually applied to a two-inch round circle area of skin on the underside of the lower forearm or the inside of the upper arm with a cotton-tipped swab. The first application should consist of a 10% solution (12 grams of DNCB crystals dissolved in 1/2 cup (125 ml) acetone). After a period of time this should be washed off.

This is called the sensitising application, which is thought to allow T-lymphocytes to recognise the DNCB and circulate throughout the body. No sooner than one month later, a 2% (2.4 grams in 1/2 cup) should be applied to the same place; the skin should redden slightly to moderately with an itching or burning sensation.

This shows that sensitisation has succeeded. Thereafter, weekly treatment can begin, applying the solution to different sites e.g. arms, legs, trunk. If blistering or weeping occurs, reduce the strength of the solution to 0.2% (0.24 grams per 1/2 cup) or 0.02% (0.024 grams per 1/2 cup). Try to maintain regular weekly applications, as unusually strong reactions may result if longer intervals are left between treatment.

DNCB solution should be stored in airtight amber bottles not plastic containers. If the container is not airtight acetone will evaporate, leaving a stronger solution that may burn. DNCB users recommend avoiding excess sun or any type of ultraviolet light as this is said to suppress the treatment effect. Skin creams that contain cortisone are also said to suppress DNCBs effects.

Getting it

99% pure DNCB crystals can be bought from some photographic chemical suppliers or from US buyers' clubs such as the Healing Alternatives Foundation. DNCB is not available through the NHS.

Key research

Mills treated HIV-positive individuals with DNCB in an open study. Improvements in T-cell fuction were observed in 6 participants with AIDS. In participants with KS, mucocutaneous lesions were reduced in size, thickness, number and colour.

Traub (1995) treated 19 HIV-positive people in Brazil with weekly applications of DNCB for an average period of 21 months. All participants had significant weight gain. Two (11%) developed parasitic infections during the course of the study, whereas among untreated historical controls the rate of parasitic infection was 45.2% over 21 months. Mean CD4 counts increased from 398 to 461, and mean CD8 counts increased from 976 to 1217.

Traub (1997) compared the effects of DNCB among 29 people with a control group of 6 people who declined treatment after the first application of DNCB. Followed for approximately 18 months, this trial found people receiving treatment had significant increases in CD4 counts and body weight, while people not on treatment had significant decreases in CD4 and CD8 counts .

Stricker (1993) reported that in a pilot study DNCB application was associated with an increase in CD8 cells and natural killer cells and a decrease in viral load in HIV-positive people, who remained clinically stable for up to 27 months. In another study, Stricker found that DNCB improves delayed-type hypersensitivity skin test responses, indicating the DNCB enhances immune functioning (1995).

Stricker (1997) reported a reduction in viral load from a half to greater than one log among 8 patients at various stages of HIV disease treated with weekly topical DNCB after 3-4 months on treatment. None was taking anti-retroviral therapy.

References

Mills LB. Stimulation of T-cellular immunity by cutaneous application of dinitrochlorobenzene. J Am Acad Dermatol 14(6):1089-1090, 1986.

Stricker RB et al. Pilot study of topical dinitrochlorobenzene (DNCB) in human immunodeficiency virus infection. Immunol Lett 36(1):1-6, 1993.

Stricker RB et al. Improved results of delayed-type hypersensitivity skin testing in HIV-infected patients treated with topical dinitrochlorobenzene. Journal of the American Academy of Dermatology 33(4): 608-611, 1995.

Stricker RB et al. Decrease in viral load associated with topical dinitrochlorobenzene therapy in HIV disease. Res Virol 148(5):343-348, 1997.

Traub A et al. Use of dinitrochlorobenzene (DNCB) as an immune modulator in HIV-positive patients: a pilot study from Brazil. Blood 86(10)(S1):935a, abstract 3728, 1995.

Traub A et al. Topical immune modulation with dinitrochlorobenzene in HIV disease: a controlled trial from Brazil. Dermatology 195:369-373, 1997.