A mast cell is a connective tissue cell that is an important component of the immune system and plays a role particularly in allergic reactions and inflammatory processes. It's found in abundance in tissues that come into contact with the outside environment, such as the skin, respiratory tract and digestive system. Various mediators, such as histamine, heparin, prostaglandins, cytokines and leukotrienes, are stored within mast cells. These mediators are released particularly during IgE-mediated allergic responses, leading to symptoms such as itching, redness, swelling and blood vessel dilation. Mast cells play a role not only in allergies, but also in defence against parasitic infections, tissue repair processes and the formation of new blood vessels.
These cells also play an important role in dermatological conditions, being involved in the pathogenesis of conditions such as urticaria, atopic dermatitis and mastocytosis.