Analysis of Positive Patch Test Allergens in Allergic Contact Dermatitis Patients with Atopic Dermatitis.

Background: There has been debate regarding whether patients with atopic dermatitis (AD) have an altered frequency of contact allergen sensitization. Increased exposure to topical medications and moisturizers as well as impaired skin barrier function increase the risk of contact sensitization, whereas the Th2-skewed inflammatory pathway of AD is associated with a reduced risk.

Objective: This retrospective study was performed to determine the characteristics of contact sensitization in allergic contact dermatitis (ACD) patients with a current or past history of AD.

Methods: A clinical record review was conducted for patients referred to Ewha Womans University Medical Center, for patch tests between March 2017 and March 2021. We compared the rates of contact sensitization between ACD patients with and without AD.

Results: In total, 515 patch test results were reviewed and divided into the AD group (n=53) and non-AD group (n=462). The AD group showed decreased any-allergen positivity (1+, 2+, or 3+) (56.6%) compared to the non-AD group (72.9%) (p=0.013). The positivity rate for budesonide was significantly higher in the AD group (p=0.011), while the prevalence of a positive result for balsam of Peru was higher in the non-AD group (p=0.036). Nickel sulfate, cobalt chloride, and potassium dichromate were the most common sensitized allergens in both groups.

Conclusion: Our study shows a decreased prevalence of contact sensitization in AD patients compared to non-AD patients. Clinicians should be aware of the risk of corticosteroid allergies in ACD patients with history of AD.