A mother brings her 8-year-old daughter into an urgent care clinic. The child has a dry, flaky, and peeling rash around her mouth. The mother states she has treated the rash with a number of different lotions, but the lesions persist. She is looking for information on how to make her daughter stop licking her lips, as she thinks this is causing the lesions. Upon assessment, the nurse notes circumoral blisters and honey-colored crusts. In the medical history, the mother reports her daughter has not had any other symptoms, including fever, nausea, vomiting, and malaise.
-In the lab,the specimen is Gram-stained and inoculated onto blood agar.Microscopic analysis of the slide reveals gram-positive cocci arranged in grapelike clusters,while the blood agar produces round,creamy colonies with clear areas of hemolysis.Which of the following would be the most likely causative organism?

Question

Quizplus · Accepted Answer

The gram-positive cocci arranged in grapelike clusters, along with the creamy colonies with clear areas of hemolysis on blood agar, are indicative of Staphylococcus aureus. This organism is known to cause impetigo, which presents with a dry, flaky, and peeling rash with honey-colored crusts. Streptococcus pyogenes may also cause impetigo, but it is characterized by Group A beta-hemolytic streptococci, which would produce a larger zone of hemolysis on blood agar. Human herpesvirus 3 (varicella-zoster virus) causes chickenpox and shingles, not a rash around the mouth. Pseudomonas aeruginosa is a gram-negative bacterium that is associated with wound infections and respiratory infections, but not impetigo.

A Mother Brings Her 8-Year-Old Daughter into an Urgent Care