How can I get diagnosed with MCAS?

If you are interested in getting tested for MCAS, the tests listed below are recommended.

1. Plasma histamine: normal range 28-51 ug/L.

2. N-methylhistamine 24-hour urine: normal range less than 200 mcg/g.

3. Plasma prostaglandin D2. Should restrict use of NSAIDs (Motrin, Advil), aspirin, ASA, or anything containing aspirin for 5 days.

4. Prostaglandin D2 (PGD2)24-hour urine. Restrict use of NSAIDs for 5 days.

5. Chromogranin A: Should restrict use of proton pump inhibitors (PPIs) and H2 blockers (Pepcid and Zantac) for 5 days.

6. Prostaglandin 11-beta F2 Alpha (PGF2alpha) 24-hour urine. Restrict NSAID use for 5 days.

7. Serum tryptase. Rarely elevated in MCAS. Normal range less than 11.5 ng/ml.

8. Leukotriene E4 24-hour urine. Restrict NSAID use for 5 days.