Sensitivity and specificity of the modified epicutaneous patch test in the diagnosis of respiratory allergy to Dermatophagoides pteronyssinus

Abstract

Background: The skin prick test is recognized as the gold standard for the specific diagnosis of allergy. Objective: To determine the sensitivity and specificity of the epicutaneous patch test that has been modified for the diagnosis of respiratory allergy to Dermatophagoides pteronyssinus. Methods: An observational, interpretative, prolective, and transversal study. The included patients were between 6 and 49 years old, with symptoms of a respiratory allergy, and a skin test was performed on them by using the European standardized prick test and a modified epicutaneous patch test with the variable of the scarification that occurred before the antigen was applied, and its homogenization with a wooden applicator, which occurred after the antigen was applied. The levels of sensitivity, specificity, and prevalence influence and positive and negative predictive values were calculated. Results: 104 patients were included, of which 72 (69.2%) were women. The age category of the patients was 24 ± 11.3 years of age. 78.9% of the patients were diagnosed with allergic rhinitis, 1.9% were diagnosed with asthma, and 19.2% were diagnosed with both rhinitis and asthma. The prevalence of the respiratory allergy to Dermatophagoides pteronyssinus was of 62.5%; 94.23% with a correct diagnosis. The sensitivity and specificity of the test was of 93.85% and 94.87%; the positive and negative predictive values were of 96.83% and 90.24%, and the positive and negative likelihood ratios were of 18.30 and 0.06. Conclusions: The modified epicutaneous patch test was highly sensitive and specific; it decreased the risk of allergen carryover and it lowered the cost of the material that was used.

Keywords

• dermatophagoides pteronyssinus
• prueba por punción cutánea
• diagnóstico de alergia respiratoria