Delayed reactions to bouillon medium of tuberculin.

In testing persons who are negative to weak dilutions of old tuberculin, it is frequently noted that a disproportionately large reaction may occur with the stronger dilutions. The suspicion has been voiced that these reactions to strong concentrations of old tuberculin may be non-specific. The problem is of special importance in testing children prior to BCG administration. Are those who react only to a 1:100 or 1:10 strength of old tuberculin to be looked upon as previously infected and not in need of BCG, or is this a non-specific reaction, not indicative of previous exposure? Delayed reactions to old tuberculin, not caused by the tuberculoprotein per se, are theoretically possible from two causes principally: 1) Irritation of Injected materials due to acidity or alkalinity, excessive concentration of salts, or chemicals causing an inflammatory response. 2) Allergic responses to substances derived from the bouillon medium. This problem has been attacked by a number of workers. Aronson’ reported on sensitization to MA100; Furcolow2 on reactions to purified protein derivative in infants; Palmer3 on the geographic distribution of non-specific reactions; and Hart4 and Freund and Hart5 on reactions to substances in the medium. This report concerns an investigation of hypersensitivity to bouillon medium.