Blood histamine levels and eosinophil, basophil counts in urticaria.

The blood histamine levels, basophil and eosinophil counts and the percentage of vacuolated eosinophils were observed in 30 controls and 15 patients of urticaria. There was a definite rise in eosinophil and basophil count during the acute stage of the disease which decreased in the quiescent or the symptom-free stage. The behavior of blood histamine level was similar. The mechanisms involved are discussed.