Impetigo is a superficial skin infection that occurs in nonbullous and bullous (elevated lesions) forms. Beta-hemolytic streptococcus usually produces nonbullous impetigo. Coagulase-positive staphylococcus aureus usually causes bullous impetigo.Impetigo is one of the most common skin infections in children. It can occur in adults but is seen far more often in children. Impetigo is contagious and can...