Scleritis (inflammation of sclera) is a strong indication of the underlying medical problem. It can be due to fungal, viral or parasitic infection, trauma, exposure to chemicals, poisonous gases or due to post-surgical complications.
Mast cells are granulated cells typically found in connective tissue. These cells mediate immune responses to foreign particles. In particular, they release large amounts of histamine and enzymes in response to antigen recognition.
Some research has suggested that it is the release of histamine from the mast cells that hinders tumor growth.43 One example given in support is a study on histidine decarboxylase (HDC) and its effect on myeloid cells. HDC is an enzyme responsible for histamine generation that is highly expressed in myeloid cells.