What is hypersensitivity?

Hypersensitivity

1. Hypersensitivity reactions are reactions that are mostly regarded as an immune system's overreaction to its own cells.
2. It produces discomfort as well as allergic responses in certain people.
3. The type IV hypersensitivity reaction is characterized by delayed hypersensitivity reactions because it takes two or three days to develop, it's called delayed hypersensitivity. It's a response that's mediated by the cells.
4. The antigen activates the specially sensitized T lymphocytes, which recognize the antigen in a complex with the MHC II major histocompatibility complex on the surface of antigen-presenting cells, resulting in the production of lymphokines and hypersensitive reactions.