Patch testing with the active principles diluted in ethanol remains the diagnostic method of choice for the detection of delayed hypersensitivity to corticosteroids. Intradermal tests with late readings, despite detecting additional contact allergy cases, should not be routinely performed, because of an important risk of atrophy, particularly with corticosteroid suspensions.
Soria, A., Baeck, M., Goossens, A., Marot, L., Duveille, V., Derouaux, A.-S., Nicolas, J.-F., & Tennstedt, D. (2011). Patch, prick or intradermal tests to detect delayed hypersensitivity to corticosteroids? Contact dermatitis, 64(6), 313-324. https://doi.org/10.1111/j.1600-0536.2011.01888.x (Original work published 2011)