Resource restrictions in healthcare IoT devices necessitates cloud services for data processing, which is prone to single point of failure, delays, and security risks. Meanwhile, exploiting blockchain can enhance security, and data ownership while providing decentralization. Optimal solutions must guarantee confidentiality, data integrity, and access control while also being cost-effective, scalable, and compatible with existing systems. Therefore, we present EdgeLinker, a blockchain-based IoT framework that uses Proof-of-Authority consensus, integrates smart contracts for access control, and employs advanced cryptographic algorithms for secure data communication between edge and fog devices. While implementing a real-world fog testbed for performance evaluations, this paper conducts a scrutinized security analysis. This analysis includes but is not limited to Sybil attacks, consensus manipulation, replay attacks, 51% attacks, traffic analysis, message spoofing, unauthorized access, Distributed Denial of Service (DDoS), and transaction malleability. EdgeLinker has shown enhanced security and privacy at reasonable costs, making it a cost-effective and practical solution for healthcare fog applications. Compared to the state-of-the-art, EdgeLinker achieves a 35% improvement in data read time without significant changes in blockchain write-time and provides better throughput in both reading and writing transactions. Furthermore, it shows energy and resource consumption improvements and channel latency in secure and non-secure modes.