Impetigo. Bacteriologic features and renal involvement.

One hundred children with impetigo were studied with particular emphasis upon the organism causing the infection and associated renal complications. In 50 per cent of cases, Group A beta-hemolytic streptococcus grew on cultures of material from the lesions, and evidence of recent infection with this organism as shown by an elevation of antistreptolysin O titer was present in an additional 17 per cent of cases. Acute glomerulonephritis developed in three of the 66 children with bacteriologic or serologic evidence of streptococcal infection. Four other children in this group and nine children with staphylococcal impetigo had unexplained microscopic hematuria. All children with nephritis already had evidence of the disease when first seen. In most of those with unexplained hematuria, this condition was detected at the first visit. Hematuria developed in others while they were receiving systemic antibiotics. The significance of isolated microscopic hematuria is uncertain, but is seen often in association with cutaneous infection with both staphylococcus and streptococcus. Microscopic hematuria as defined is apparently not prevented by antibiotic therapy. If acute glomerulonephritis that follows streptococcal cutaneous infection is to be prevented, streptococcal impetigo will have to be treated promptly after onset.