Inability of Penicillin to Neutralize Dick and Schick Toxins

Summary and Conclusions 1. When mixtures of penicillin and Dick toxin were injected intracutaneously into normal subjects along with parallel mixtures of Dick toxin and isotonic salt solution, no significant difference was observed in the number of positive Dick tests in the 2 series. Incubation of the mixtures, previous to testing, did not influence the outcome. 2. Similar results were obtained with Schick toxin. 3. Penicillin injected into an area of rash of patients with scarlet fever did not cause blanching. 4. Dick positive patients receiving penicillin for an unrelated disease did not become Dick negative after a week of penicillin therapy. 5. It is concluded that penicillin has no neutralizing effect upon Dick or Schick toxin. We wish to thank Dr. John H. Hanks for his interest and advice.