Your last patient of the evening is a 42-year-old veterinarian who recently returned from a trip to Mexico where he injured the dorsum of his right hand on a cactus spine. He states that he was able to remove the entire spine and the site subsequently became infected. He put himself on cephalexin and everything improved after a few days. He completed a seven-day course two days ago. Now the infection seems to be returning and he is hoping you could write him a prescription for a stronger antibiotic.
His medical history is pretty unremarkable. His physical exam is only notable for mild rubor, calor, tumor and dolor just proximal to the dorsal right 3rd MCP joint. The puncture site is barely visible. There is no drainage or fluctuance, and you don’t see a pustule. His range of motion is slightly decreased, but all in all, the infection looks pretty mild.
You decide that because things don’t look too bad, he really doesn’t need any IV antibiotics, but you do give him a dose of oral Bactrim along with a Tdap booster that is overdue. Treatment failure leads you to consider a few possibilities. You have some suspicion for a resistant organism, but you’re even more worried that the tip of the cactus spine is still in your patient. An X-ray probably won’t pick it up, CT is probably overkill, as is an MRI, which you couldn’t get after hours anyway. You decide that ultrasound is going to be your imaging modality of choice, as it is especially good at finding wooden foreign bodies.
You write your orders, but about fifteen minutes later the nurse comes to you and says that your patient wants to leave now, and it will be at least an hour wait before he can get his ultrasound through radiology. Fearing that either your Press Ganey scores or your malpractice rates could take a hit with your plan-A or your patient’s plan-B, you decide on plan-C. You find the ED ultrasound machine, fire it up, and set the zoom to maximum. You then obtain the following images. The one on top is the infected hand. The other is a comparison view. What do you see? What should you recommend to your patient?
click on image to enlarge
Conclusion on next page