In vitro histamine release from leukocytes in penicillin allergies.

The definite diagnosis of Type I allergy against penicillin is very important. The in vivo tests used for this purpose may have some disadvantages for the patient. Among the in vitro tests used for the evidence and differential diagnosis of Type I allergy against penicillin, the determination of histamine release from leukocytes and the detection of IgE by the RAST test are the most promising. We have used the test of histamine release from leukocyte in this study of 18 cases, nine of whom had Type I hypersensitivity reactions to penicillin and comprised the study group, the rest were control cases. The per cent of histamine release in the control group was "zero" while in the study group it ranged from 3.9 to 51.7 per cent. The results indicate that the method used in this study is a sensitive and reliable method for the diagnosis of Type I penicillin allergies.