Animal Models of Inflammatory Pain

Animal models of inflammatory pain have been widely used to study the mechanisms of tissue injury-induced persistent pain. A variety of inflammatory agents or irritants, including complete Freund’s adjuvant, carrageenan, zymosan, mustard oil, formalin, capsaicin, bee venom, acidic saline, lipopolysaccharide, inflammatory cytokines, and sodium urate crystals, have been used to produce tissue injury and hyperalgesia in such structures as cutaneous/subcutaneous tissues, joints, and muscles. Additionally, models of pain hypersensitivity have also been established with injuries produced by burning, freezing, and ultra irradiation. Although these models do not simulate every aspect of chronic pain, they do model key features of human inflammatory pain. Studies in animals give insight into certain aspects of human pain conditions and lead to improved pain management for patients.