Mast cell activation syndrome (MCAS) and mastocytosis are two conditions that affect how mast cells function. There is no cure for these conditions and in most cases they are present because of a genetic predisposition. Treatments focus on improving the dermatological, gastrointestinal, respiratory, and other symptoms that result from overproduction of certain chemical mediators. Antihistamines are one of the most frequently used types of medications for managing these symptoms. The…