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.
Histamine is a chemical that is normally produced in the body and stored in allergic cells, such as mast cells and basophils. In people with allergies, histamine is released from these cells in a response to allergens.