AAFM Boards Dermatology Practice Test

Staphylococcus aureus is the principal pathogen in nonbullous impetigo. This type of skin infection is characterized by superficial vesicles that rupture and form crusted lesions, typically occurring in children. Staphylococcus aureus is particularly adept at colonizing the skin and mucous membranes, which is crucial in the development of impetigo.

The bacteria can invade areas of broken skin, whether from scratches, insect bites, or other traumas, leading to infection. The production of exoenzymes and toxins by Staphylococcus aureus contributes to its virulence, allowing it to effectively spread and cause skin lesions.

Nonbullous impetigo often presents as honey-colored crusts, which are a result of stagnant serum that becomes colonized by this specific bacterium. The nature of Staphylococcus aureus to cause localized skin infections and its common presence on the skin makes it the leading cause of nonbullous impetigo, setting it apart from other bacteria that are involved in different types of infections or are more prevalent in other conditions.