Wednesday, September 19, 2007

Back to School

As fall approaches, mothers start bringing their kids into the clinic for routine check-ups and vaccinations. One mother brings her eight year old son in. On exam, you find tender lymph nodes along the neck and axilla on the left. He says it hurts when you palpate them. You see this on his left shoulder:

You notice the child has a mild fever. You ask him about symptoms and he just says, "I feel sick." You look at the mother. She says, "I think he's faking it to get out of going to school. You should have seen him playing with his grandmother's kittens two weeks ago. He was full of energy."

Challenge: What is the cause of this disease?

Related Questions:
1. How might you describe the skin lesion?
2. What is the diagnosis?

Image shown under fair use.


Alex said...

cat scratch disease. hm, but you sort of fed us the answer. the symptoms wouldn't have been specific enough to guess cat scratch disease

Craig said...

Back to School

The skin lesion might be described as an erythematous, tender papule. This occurs at the innoculation site. The painful regional lymphadenopathy paired with the history suggest cat scratch disease. This is caused by Bartonella henselae, a gram-negative bacterium. It occurs more often in males and 80% cases are in patients younger than 21. It is a self-limiting disorder with excellent prognosis. Usually a kitten is responsible.

Sources: Wikipedia, eMedicine, Brown University Department of Pediatric Surgery