By a double blind cross over design, prophylaxis of streptococcal skin disease by long acting benzathine penicillin was studied in 78 children from 18 families with a history of experience with this problem. The prevalence and the incidence of skin lesions were significantly reduced during a 6 wk follow up period after penicillin therapy. The duration of protection was variable, but the majority of children were protected for at least 4 wk. Less protection was observed in younger children, due du to either age or dose related factors. Skin lesions were more prevalent in younger children, irrespective of the type of injection given. Group A streptococci were more frequently recovered from normal skin than from skin lesions after penicillin administration. No indirect protection from disease that might have been conferred by other family members who received prophylaxis was observed in children who, because of allergy, received no injections. Ninety five percent of streptococcal isolates were M typable, and differences were noted in the distribution of specific serotypes from various body sites.
Bibliographical noteFunding Information:
Received for publication July 2, 1973, and in revised form October 3, 1973. This work was supported by research grant no. AI 09527 from the U.S. Public Health Service and was conducted under the sponsorship of the Commission .on Streptococcal and Staphylococcal Diseases, Armed Forces Epidemiological Board, and with the sponsorship and support of the U.S. Army Medical Research and Development Command under research contract no. DADAI7-70-C-0081. The cooperation of the physicians and administrative and nursing personnel of the U.S. Public Health Service Hospital at Red Lake, Minnesota, and of members of the Red Lake Comprehensive Health Services is gratefully acknowledged. We thank Margaret Ragan and Dwight Johnson for valuable assistance in typing the streptococcal strains. We also thank Wyeth Laboratories, which provided the benzathine penicillin. Dr. Wannamaker is a Career Investigator of the American Heart Association. Dr. Dajani is a recipient of Research Career Development Award no. 5K04 AI-42604-04 from the National Institute of Allergy and Infectious Diseases. Please address requests for reprints to Dr. Patricia Ferrieri, Department of Pediatrics, Box 134 Mayo Building, University of Minnesota, Minneapolis, Minnesota 55455.