Immunologic Studies in Rheumatic Fever

Summary Cutaneous reaction to the M fraction of 25 known Griffith types of hemolytic streptococcus was studied in rheumatic children, their normal siblings, and normal children. The incidence of positive cutaneous reaction in normal children is 65 per cent as compared with 83 per cent in rheumatic children.5 The incidence of positive cutaneous reaction in the normal siblings of these rheumatic children is the same as in rheumatic children. The cutaneous reactions of normal children are of a significantly milder degree than those of rheumatic children and their siblings; the highest degree of reactivity was found in the normal siblings of rheumatic children. The incidence and the degree of cutaneous reaction to the M fraction of the hemolytic streptococcus is not influenced by the age of the child, between the ages of 6 and 16, or by the rheumatic status: active cases do not show a higher incidence or degree of cutaneous reactivity. Cutaneous reactivity to specific M fraction in rheumatic children diminishes only slightly with the lapse of time following an acute rheumatic episode.