Results from an extended study on the reliability of a questionnaire for the diagnosis of sensitive skin: Confirmations and improvements

Objective A recently proposed self‐assessment questionnaire aimed at diagnosing sensitive skin provided promising results in a relatively small population. The main objectives were: (i) to assess the reliability of the aforementioned questionnaire in a larger population and verify the cut‐off score previously found to predict skin sensitivity (defined as positivity to LAST, lactic acid stinging test) and (ii) to define a formula that yields the probability of a positive LAST result. Methods Adult volunteers were included in this observational, cross‐sectional, extended study. Both LAST‐positive subjects, who were considered as having sensitive skin (‘patients’) and negative ones (‘controls’) completed the questionnaire, which concerned sensitivity to possible triggers of unpleasant skin sensations in real life. A cumulative score (questionnaire‐based skin sensitivity score, 0–10) was calculated from the sum of all items. Results Three hundred and sixty‐four subjects were enrolled, 214 patients and 150 controls. The mean questionnaire‐based skin sensitivity score was significantly higher among patients than controls. Using two different methods, cut‐off values of 4 and 5 were defined for the identification of LAST‐positive subjects, with 76.6% and 72.8% accuracy, respectively. Scores below 4 or above 5 showed a high (80% or better) negative or positive predictive value, respectively. The coefficients found that in multivariate analysis for each questionnaire item, gender and age allowed us to calculate the probability of LAST positivity with higher precision taking into account the ‘relative weight’ of each factor. Conclusion With small variations in the results, the self‐assessment questionnaire confirmed its reliability for diagnosing sensitive skin in clinical practice. Résumé Introduction Un questionnaire d'auto‐évaluation récemment proposé visant à diagnostiquer la peau sensible a fourni des résultats prometteurs dans une population relativement petite. Les principaux objectifs étaient: (i) d'évaluer la fiabilité du questionnaire susmentionné dans une population plus large et de vérifier la valeur du cut‐off précédemment trouvé pour prédire la sensibilité cutanée (définie comme la positivité au LAST, de l'anglais « test de piqûre d'acide lactique »), et (ii) de définir une formule qui donne la probabilité d'un résultat LAST positif. Méthodes Des volontaires adultes ont été inclus dans cette étude observationnelle, transversale et étendue. Les sujets LA