Right now the only one I know of is Dr. Jonathan Bernstein, but from what a few patients reported he seems dismissive of a patient's suspicion of MCAD saying something like "Oh you don't want that, besides it's so rare." (MCAD is recently believed common by some top MCAD researchers)

And one lady on here who strongly suspected MCAD went to him. Her tests came back normal, which is common with MCAS, but some doctors apparently incorrectly think that rules out MCAD, so he diagnosed her with multiple chemical sensitivity and told her all she could do was avoid her triggers. From that I presume he didn't give her any prescriptions. I think many other MCAD specialists such as Dr. Afrin would have strongly suspected MCAD and tried some prescriptions and maybe more tests.

But maybe Dr. Jonathan Bernstein has improved since then.

You asked about Dr. Hostoffer in another post. I don't know about him, but I presume you've read or heard something that indicated he may be familiar with MCAS. I would call him and ask, and then report back so others in Ohio can know. Every new doctor added to the list helps.

For patient experience with Dr. Jonathan Bernstein(last post):
http://mastcelldisorders.wallack.us/yabb/YaBB.pl?num=1311096016

Dr. Jonathan Bernstein contact info(under Ohio):
http://tmsforacure.org/patients/research_centers_1.php