The Benefit of Patch Testing With a Corticosteroid at a Low Concentration

BACKGROUND: Patch testing with corticosteroid marker molecules is advocated because testing with all available corticosteroids is impossible in clinical practice. Most commonly used are budesonide, tixocortol pivalate, and hydrocortisone-17-butyrate. We have been patch testing not only with the three markers, but also with two corticosteroid mixes, each consisting of different concentrations of the three markers. OBJECTIVE: We describe a patient allergic to tixocortol pivalate, who was diagnosed by using a lower patch test concentration that recommended, 0.1% in petrolatum, as well as a weak corticosteroid mix, 0.202%. METHODS: The patient was patch tested to a standard series, including the two corticosteroid mixes and its three constituents. RESULTS: None of the corticosteroid preparations were positive on the first ordinary reading day, day 3, whereas both tixocortol pivalate at 0.1% and the corticosteriod mix at 0.202% were positive on the second ordinary reading day, day 7, whereas all tested corticosteroids in the standard series gave positive reactions on d10. CONCLUSION: The possible benefit of patch testing with a corticosteroid at a low concentration is supported, as is the significance of late readings beyond D4.