To the best of my knowledge, I don't have mastocytosis, but I suspect that I may have Mast Cell Activation Syndrome (MCAS). Here is a web link with "Diagnosis and Classification" summaries for both conditions:
A "Minor" criterion for mastocytosis under the "Diagnosis and Classification" protocol cited in the link above is "Serum total tryptase > 20 ng/mL (does not count in patients who have ANHMD-type disease.)" I could not find what the acronym "ANHMD" means on the Internet, but another web link containing "WHO criteria for systemic mastocytosis";
says one "Minor Criterion" is "d. Serum total tryptase persistently >20 ng/ml (not a valid criteria in cases of systemic mastocytosis with associated clonal hematologic non-mast-cell lineage disease)."
Diagnostic criteria listed in the first web link for MCAS also includes tryptase measurement, but elevated tryptase is not always mandatory for a diagnosis of MCAS either, depending on other findings.
Another web link (paper) that might be of interest is:
"Pharmacological treatment options for mast cell activation disease"
Some people (perhaps including me, it's too early to tell) can get significant relief from MCAS symptoms with widely available and inexpensive medications; whether they have been "officially" diagnosed with MCAS or not. I don't know if this possibility also applies to people with mastocytosis. The last web link above may give you more insight about this possibility.
One last web link (below) is a listing of mast cell disease treatment and research centers.
Last week I saw an allergy/immunology specialist for the first time. We agreed that for me, getting an official MCAS diagnosis won't be necessary if the simple medications he prescribed and recommended for me "work." So far (knock on wood) I believe that they are helping significantly.
Good luck and best wishes.