Contamination of intradermal skin test syringes.

Syringes used in intradermal skin testing have commonly been used for multiple patients. Recently the safety of this practice was questioned, raising the possibility that these syringes may transmit disease from one patient to another. Since this practice is so widespread and because of a scarcity of articles linking the spread of disease with this practice, we repeated these studies and performed other experiments to test this hypothesis. With the use of Escherichia coli, Staphylococcus aureus, and tritiated thymidine, we found contamination of syringe contents that indicated a clear potential for common syringes to spread disease. These studies and studies reported elsewhere suggest that common syringes should not be used in skin testing.