Histaminuria from histamine-rich foods.

Using a highly specific and sensitive assay, the histamine content of foodstuffs and the effect of ingesting these foodstuffs on urinary histamine excretion were measured. Certain vegetables (spinach, eggplant), cheeses (Parmesan, blue, Roquefort), and red wines (Chianti and Burgundy) had a high content of histamine. Although only 0.21% of the ingested histamine was excreted unchanged in the urine, the histamine content of some of the foods was so high (Parmesan cheese, 185 micrograms/g; spinach, 60 micrograms/g; baked eggplant, 26 micrograms/g) that they caused histaminuria. Patients collecting urine for analysis for 24-hour histamine excretion for diagnosis of systemic mastocytosis or carcinoid syndrome should avoid intake of these foods and beverages on the day of the urine collection.