Study Explores Unreported Allergic Contact Dermatitis due to Salicylic Acid

A recent study from a dermatology clinic, published in the recent issue of Contact Dermatitis journal highlighted the underreported issue of allergic contact dermatitis (ACD) which is caused by salicylic acid (SA). Despite the well-documented cross-reactivity among salicylates, the reports of such reactivity that specifically involved SA have been scarce.

The objective of the study was to describe the clinic's experience with patch testing for SA by highlighting seven notable cases of allergic reactions. The study analyzed results from patch tests conducted between January 1, 2020 and February 9, 2024 using a 5% SA in petrolatum solution.

Out of 489 patients who underwent patch testing for SA, 27.5% (approximately 135 patients) were tested. Among these, 21 participants showed positive reactions. The breakdown of reactions included seven doubtful (+/−) cases and 14 weak positive (+) cases. Also, there were no strong or extreme positive reactions observed. Four more irritant reactions were documented which indicated some level of irritation but not necessarily an allergic response.

Of the 14 weak positive reactions, 7 cases were deemed to have definite or probable clinical relevance which means the allergic reaction was likely connected to their clinical symptoms. Also, five of these seven relevant cases also expressed reactivity to other salicylates that suggests a probable cross-reactivity.

The study concludes that ACD to SA is likely underreported due to insufficient testing. The findings indicate that patch testing with 5% SA in petrolatum is generally tolerable for patients which showed minimal significant irritation. The probable cross-reactivity between SA and other salicylates underlines the need for more comprehensive testing and awareness among clinicians.

The outcomes of this research emphasize that while SA appears to be a primary sensitizer in some cases, further studies are imperative to determine its role as a potential marker for the salicylate allergy. This discovery could lead to better diagnostic practices and management strategies for the patients with suspected salicylate allergies.

The results of this study highlight the necessity for increased vigilance and reporting of ACD cases related to SA. Given the widespread use of SA in various skincare and medicinal products, understanding its allergenic potential is highly crucial for both patients and healthcare providers. Improved awareness and more rigorous testing protocols could lead to more accurate diagnoses and enhanced patient outcomes in the participants with salicylate sensitivities.

Source:

Brumley, C., Arora, P., Neeley, A., & Hylwa, S. (2024). Allergic contact dermatitis to salicylic acid: A case series of relevant sensitization. In Contact Dermatitis. Wiley. https://doi.org/10.1111/cod.14573