To the Editor.—
Photopatch tests have traditionally been irradiated 24 hours after application of the photoallergen.1,2 Willis and Kligman found that the delay between application and irradiation was unnecessary in ten subjects highly sensitized to tribromsalan.3 They repeatedly compared immediate with 24-hour irradiation, and never failed to elicit a response with the former. The object of this communication is to report the case of a patient who had a false negative reaction to immediate photopatch testing with tribromsalan.
Report of a Case.—
A 60-year-old man, first seen on Oct 7, 1969, gave a 20-year history of atopic dermatitis which had become much worse in the last two years. Examination showed a generalized eczematous dermatitis, sparing only the area covered by his under-shorts. Systemic treatment with triamcinolone (8 mg, twice daily) produced considerable improvement so that the active areas were limited to the face and hands, producing a typical
Shelmire D. FALSE NEGATIVE IMMEDIATE PHOTOPATCH TEST TO TRIBROMSALAN. Arch Dermatol. 1971;103(2):223-224. doi:10.1001/archderm.1971.04000140109021