Allergen Sensitization in Atopic Dermatitis: Distinction from Controls and Prediction of Respiratory Allergies.

introductionAtopic dermatitis (AD) is a common inflammatory skin condition characterized by epidermal barrier dysfunction and immune dysregulation, affecting both children and adults. This study aimed to determine the prevalence of common allergen sensitizations in patients with AD, compared with controls without allergic diseases, and to identify those associated with an increased risk of asthma or allergic rhinitis.

methodsWe conducted a cross-sectional study including patients with AD and age- and sex-matched controls selected by propensity score matching from the Center of Allergy and Clinical Immunology, Vinmec Times City Hospital. Total IgE levels and specific IgE sensitization to common allergens were documented using an extract-based multiplex assay.

resultsBoth the AD and control groups each comprised 452 patients and were comparable in age, median (IQR, range): 7 (1-29, 0-84), and sex distribution (51.11% female). Sensitization to at least one allergen was observed in 59.51% of patients, with a mono-sensitization rate of 11.73% and a poly-sensitization rate of 47.79%. House dust mites had the highest sensitization rates among AD patients in our study, with sensitization rates for Dermatophagoides pteronyssinus, D. farinae, and Blomia tropicalis at 29.65%, 26.99%, and 11.5%, respectively. Eggs and milk were the most common food allergens, with sensitizations rates of 20.58% and 12.61%, respectively. Although sensitization rates were high, the prevalence of true clinical allergy was much lower, underscoring the need for cautious interpretation of test results in conjunction with clinical symptoms. Age-related differences were evident: younger children were more often sensitized to food allergens, older children and adolescents to respiratory allergens, and elderly patients to cockroach, and Candida albicans. Additionally, sensitization to C. albicans, D. pteronyssinus, D. farinae, cat dander, dog dander, rice grain, barley flour, and rye flour was significantly more frequent in patients with AD compared to individuals with no allergic diseases. Such sensitization was also associated with a higher risk of respiratory allergic comorbidities, suggesting the potential role of these allergens as distinctive markers of atopy.

conclusionThis study highlights the importance of understanding allergen sensitization in patients with AD to optimize management strategies, particularly in Vietnam, where house dust mite sensitization is highly prevalent. Allergen avoidance and allergen-specific immunotherapy could be beneficial as add-on therapies for AD.