The relationship between atopy and allergic contact dermatitis in Israeli patients

Introduction
Whether individuals with atopic diseases have a different risk of contact allergy compared to those who are non-atopic is controversial and data are conflicting.

Aim
To explore the association between atopy and allergic contact dermatitis (ACD).

Material and methods
This retrospective cross-sectional study included 301 patients referred to a tertiary clinic to evaluate ACD. Demographic details including personal and familial mucosal or cutaneous atopic status were recorded. Patch tests were tailored to their clinical presentations and relevant exposures.

Results
At least 1 positive patch test reaction was observed in 177 patients (59% of the study cohort), of which 52% had a history of atopic diseases, compared with 44% of patients with a negative patch test result (p = 0.2). Additionally, 147 patients had an atopic background, of which 92 (62%) had ≥ 1 positive patch test result, compared with 55% of non-atopic patients (p = 0.2). Nickel sulphate was the most common contact allergen (13.4% of the patch test reactions).

Conclusions
We identified a positive tendency for atopic diseases among individuals with ACD and vice versa. Our study supports the aggregate data from previous studies despite the non-significant differences between the study and control groups. However, further research performed in larger populations of patients is necessary to evaluate the real association between atopy and ACD on a solid basis. Our results indicate the necessity of systematic patch testing in patient setups with atopic background and chronic dermatitis.