Under-diagnosis of atopic dermatitis in Puerto Rican children

Background: Little is known about atopic dermatitis (AD) among children in Puerto Rico. Objective: To examine risk factors and identify approaches to better diagnose AD in Puerto Rican children. Methods: Case-control study of AD among 540 children aged 6-14 years in San Juan, Puerto Rico. AD was defined as: 1) physician-diagnosed AD, 2) RAST-AD: AD symptoms plus >= 1 positive IgE to allergens, and 3) STR-AD: AD-symptoms and skin WA reactivity to >= 1 allergen. Logistic regression was used for the multivariable analysis. We also evaluated the diagnostic performance of various approaches by comparing their sensitivity, specificity, positive predicted value [PPV], negative predictive value [NPV], and area under curve [AUC]). Results: Of the 70 children with STR-AD, only 5 (7.1%) had PD-AD. In children without asthma, a positive IgE to Dermatophagoides (D.) pteronyssinus and signs of mold/mildew at home were significantly associated with 3.3 and 5 times increased odds of STR-AD, respectively. Among children with asthma, private/employer-based health insurance and a positive IgE to D. pteronyssinus were each significantly associated with approximately twofold increased odds of STR-AD. A combination of current eczema symptoms and a positive IgE to D. pteronyssinus yielded a sensitivity >= 70%, specificity and NPV >= 95%, PPV >= 88%, and an AUC >= 0.85 for STR-AD. Replacing a positive IgE to D. pteronyssinus with a positive IgE to >= 1 allergen slightly increased sensitivity without affecting other parameters. Conclusions: AD is markedly under-diagnosed by physicians in Puerto Rico. This could be improved by assessing eczema symptoms and measuring IgEs to common allergens.