In the article by Taylor et al,1 there looms a dilemma of which patch tests we are to believe. The report discusses patches where erythema, irritation, and positive results in the nature of 1+'s are seen in various patients who at some time in the past had used doxepin hydrochloride cream. There were no adequate controls. In addition, the article cursorily mentions the Draize-Shelanski-Jordan repeat-insult patch test.
This Draize-Shelanski-Jordan test2 is the standard test for seeking out allergic contact dermatitis for a premarketed topical drug or cosmetic.3 The article mentions that nearly 500 patients had this performed with no positive results occurring. I confirmed this with a telephone call to the scientists at GenDerm Corp, Lincolnshire, Ill (June 1996). This test has been the standard for more than 50 years and I know of no instance where a negative test result later was shown to have
Rapaport MJ. Allergic Contact Dermatitis From Doxepin Cream. Arch Dermatol. 1996;132(12):1516-1517. doi:10.1001/archderm.1996.03890360110024