We here propose a study to update and reach quality assurance of the classification of allergic and hypersensitivity conditions in international classification systems. The Allergic and hypersensitivity conditions section has indeed been recently built into the new ICD-11 framework and we aim to reach its quality assurance by evaluating medical records of French hospital databases. All the consecutive cases related to allergic and hypersensitivity conditions registered in the last 1 year will be selected and blind-coded by two independent coders based on the online English versions of the ICD-10 (2015 version) and ICD-11 Beta draft. The generated data will support the intra and inter-variability testing, survey among end-users and economic-impact evaluation. The economic impact of the transition from ICD-10 to ICD-11 will be analysed based on average estimated cost per day of each principal diagnosis and the effect of the classification change will be quantified by the cost variance of inter or intra diagnosis of ICD-10 and ICD-11. For the bridge procedure based on the alignment of the allergic and hypersensitivity conditions described into the ICD-10 (and ICD-10 CM US adaptation) framework to the ICD-11 beta phase, we propose the mapping and cross-linking terms methods. Meanwhile, we will start updating the allergic and hypersensitivity procedures by influencing the International Classification of Health Intervention (ICHI).