Pattern of contact sensitization in patients with and without atopic dermatitis in an Asian dermatology center.

Background: Although the traditional understanding is that contact sensitization is less frequent in patients with atopic dermatitis (AD), recent studies have shown similar or higher rates of positive patch-test results in AD patients.

Objectives: We sought to characterise the pattern of contact sensitization in patients with and without AD and evaluate the association between AD and contact sensitization.

Method: This was a single-center, 10-year retrospective review of patients who underwent patch testing between 2007 and 2017.

Results: There were 4903 patients (male-to-female ratio = 1:1.4; mean age 40.1 years) included. About half (2499, 51.0%) of all patients developed at least one positive reaction. The top five frequent reactions were to nickel sulfate (45.4%), potassium dichromate (16.0%), p-phenylenediamine (13.4%), Myroxylon pereirae (11.8%), and fragrance mix I (11.2%). The overall prevalence of contact sensitization was not significantly different between patients with or without AD. Patients with AD were less likely to develop contact allergies to budesonide and thiuram mix, and more likely to develop contact allergies to potassium dichromate.

Conclusions: Contact sensitization was detected in 50% of patients who were patch tested. Nickel sulfate was the most frequently sensitizing allergen. The prevalence of contact allergies in atopic patients is comparable to that in non-atopic patients.