Hi @rhawk314, I'd like to add my welcome and some info to add to the great info you've already received from @juy77 @frenchie333 @hsminc and others.

You may also be interested in this related discussion"
- Mast Cell Activation: https://connect.mayoclinic.org/discussion/mast-cell-activation/

Robert, you ask about Mayo Clinic and MCAS specialists at Mayo in Phoenix. Regardless of location Mayo Clinic doctors from several medical specialties work together to provide you with the best care possible. Your team may include specialists in allergic diseases, hematology, dermatology, gastroenterology, neurology, endocrinology and pathology. To submit an appointment request and ask questions about being seen at Mayo Clinic AZ, start by filling out the online form on this page http://mayocl.in/1mtmR63. Once submitted, a coordinator will arrange a phone interview to talk about your needs and whether Mayo is right for you.