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.
1 Much of the histamine in the body is produced by the granules in mast cells and basophils as part of a local immune response to the presence of invading bodies. Histamine is also made in the brain where it acts as a neurotransmitter or chemical messenger that carries signals between nerves. 2  Another important site where histamine is stored and released is in the enterochromaffin-like (ECL) cells of the stomach.