Epidemiological aspects of impetigo contagiosa in western Sweden.

200 patients with primary impetigo were studied. Staphylococcus aureus was the only organism isolated in 72.5%, beta-hemolytic streptococci, group A, in 10%, and both pathogens in 15%. 17 of the 50 streptococcal isolates were typed serologically; 11 of these belonged to potentially nephritogenic types. A majority of these cases had identical strains in the nose and throat. Hence, the primary source of skin streptococcal in this study may be the nasopharynx. Uncomplicated cases were treated with topical antibiotics, and oral antibiotics were added in 22 cases with extensive lesions, fever or a concurrent throat infection. None of the 200 patients developed acute glomerulonephritis and urinary analyses were normal at follow-up after 3 weeks.