Abstract
Blockchain has often been mentioned in recent years as being a promising innovation for the healthcare sector in that it can ensure the secure exchange and traceability of information while respecting the regulatory framework for the confidentiality and portability of healthcare data. However, concrete cases remain very rare in the literature, and we investigate relevant use cases applying blockchain in healthcare. This chapter shows how we design a blockchain-based allergy card to solve real-life issues that is register, share and trace information about drug allergies. Therefore, we iteratively use action design research to determine the needs, design solution, develop the application and evaluate outcomes by involving stakeholders in the construction and evaluation.