Allergic contact dermatitis to salicylic acid: A case series of relevant sensitization

Introduction Allergic contact dermatitis (ACD) to salicylic acid (SA) is widely unreported. Furthermore, cross‐reactivity between SA and other salicylates has not been reported despite well‐documented in‐group salicylate cross‐reactivity. Objective To describe our clinic's experience patch testing to SA, highlighting seven cases of relevant reactions and concomitant reactivity with other salicylates. Methods Results of patch testing to 5% SA in petrolatum between 1 January 2020, and 9 February 2024, are reported. Seven cases of relevant reactions to SA are detailed. Results A total of 489 patients (27.5%) were tested to SA, 21 of which were positive: 7 doubtful (+/−), 14 weak positive (+), and no strong/extreme positive reactions. Four irritant reactions were documented. Of the 14 weak positive (+) reactions, 7 had definite or probable clinical relevance, 5 of which also reacted to other salicylates. Conclusions ACD to SA is likely underreported due to a lack of testing. In our experience, testing SA 5% petrolatum is tolerable without significant irritation. Cross‐reactivity between SA and other salicylates is probable. Though SA appears to be the primary sensitizer in some cases, more studies are needed to understand its possible role as a marker for salicylate allergy.