Selective utilization of clinical diagnosis in treatment of pharyngitis.

Exudate, adenopathy, and fever were used to predict clinically whether pharyngitis was streptococcal, nonstreptococcal, or questionable in 466 adults and 234 children. Clinical accuracy was: nonstreptococcal - adults 94.6 percent, children 86.9 percent; streptococcal - adults 44.2 percent, children 53.5 percent. Significance of results was determined by calculating the cost of routine cultures compared to risk of rheumatic fever. The economic justification of cultures was lowest in nonstreptococcal adults, streptococcal adults, and streptococcal children. Therapy of streptococcal patients presented an additional risk: anaphylaxis. The fatality risk after penicillin injection compared to the increased risk of rheumatic fever after oral penicillin is: adults 7.5 percent (clinical diagnosis), 3.3 percent (laboratory diagnosis); children 1.8 percent and 0.8 percent respectively. It is recommended that throat culture be obtained for all questionable patients and clinically nonstreptococcal children. Penicillin should be administered orally in the majority of adults.