Topical Sensitizers in Alopecia Areata

Amy J. McMichael; Robert L. Henderson, Jr.


Dermatology Nursing. 2004;16(4) 

In This Article

Application Methods

Once topical sensitization has been appropriately selected for treatment of AA, the patient must initially be sensitized to the chemical. In our clinics, SADBE is used and sensitization begins with a 2% solution in acetone applied to a 10 to 16 cm2 area on exposed skin. Usually the side of the scalp suffices, but the buttock may serve as an alternative. Using a cotton-tipped applicator dipped twice in the solution provides adequate exposure. As the acetone solvent evaporates quickly, the residual sensitizer is not visible. Following application, the sensitized area should not be washed for 24 hours.

Though rarely used as a self-treatment, we use SADBE in this manner because the distance patients travel to our clinic precludes weekly returns. Self-treatments can begin 2 weeks following sensitization with 0.001% to 0.1% solutions, again applied with a cotton-tipped applicator to the entire affected area. Patients should be reminded to keep the solution refrigerated. Regimens can then consist of every other day to once weekly applications. We usually begin a regimen of 1 to 2 times a week and allow increasing or decreasing the frequency based on the reaction. The strength of solution used can also be titrated to pruritus at subsequent followup visits allowing 4 to 6 months between dosing changes. We use solutions of 0.0001%, 0.001%, 0.01%, 0.1%, 1%, 2%, and 4%. For all the sensitizers, inducing a clinically evident allergic response appears necessary, but not a fulminant dermatitis. Regrowth is usually evident by week 18 (see Figures 2, 3, & Table 1 ) (Hull, Cunliffe, & Norris, 1990).

Alopecia areata before treatment

Following treatment with squaric acid


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