Atopy Associated With Positive Patch Test and Possible Allergic Contact Dermatitis.

BACKGROUND: Atopy is a genetic predisposition to the development of allergic reactions and the increased production of immunoglobulin E (IgE) upon exposure to environmental antigens. Clinical manifestations of atopy include asthma, atopic dermatitis (AD), and allergic rhinoconjunctivitis (ARC).

OBJECTIVE: To determine if cutaneous delayed hypersensitivity reactions (CDHRs) as assessed by patch testing are higher among patients with a history of atopy and with a familial predisposition to atopy.

METHODS: For this study, we reviewed the patch test database of the UBC Contact Dermatitis Clinic over a 4-year time span. A personal history of asthma, AD, and ARC was recorded. In addition, a family history was obtained and manifestations of atopy in family members were noted.

RESULTS: A total of 1515 patients were included in this study. Our data show that the odds ratio (OR) of a positive patch test with a personal history of atopy was 1.39, while the OR of a positive patch test with a family history of atopy was 1.69. Conversely, a personal history of respiratory atopy did not significantly affect the probability of a positive patch test, with an OR of 1.03.

CONCLUSION: We conclude from our study that patients with a personal or family history of atopy have an increased risk of allergic contact dermatitis (ACD). These results provide further evidence for the link between atopy and ACD and suggest that children of atopic parents should avoid potential contact allergens and would likely benefit from prophylactic emollient use.