This is a case of a 10 year-old boy who presents with a progressive, erythematous swelling on his posterior neck without fevers. He has been taking amoxicillin-clavulanic acid without improvement. Please click here for the complete case presentation.
Thank you to Dave, Paul, Dewesh, and Jennifer for their helpful commentary. Also a shout out to Asha for making the effort and being thwarted by the iPad. Click here and scroll up to see everyone's comments.
Here's what you said about the case.
1. Would you obtain any imaging in this case?
2. If you could get only one lab, what would it be?
Hot Seat Response
by Jim Chamberlain
Whenever I’m asked to evaluate a mass or swelling, I try to get at three important questions. First, what lives in that area? Second, is there something herniated and incarcerated that I need to do something about immediately to prevent morbidity? Third, does this seem infectious (i.e. something I can treat in the ED)? While I always keep malignancies, atypical Mycobacteria (especially in this region), TB, and cat scratch disease in my differential, these are less common than simple reactive lymphadenopathy and soft tissue bacterial infections. I would certainly probe the family for travel history, history of someone with possible TB in the family, and the presence of a cat who likes to scratch.
Regarding the first question, the anatomy of the posterior neck is straightforward. There is skin, muscle, some lymph nodes, and then the deeper vessels and bones of the spine. One important thing to note is that the lymph nodes under the trapezius muscle may drain down from the head or up from the thorax, depending on how caudad you are. The mass described in this patient sounds superficial as the description is “overlying trapezius.” I will take the examiner’s word for it and dismiss problems with the deeper structures, including the lymph nodes. Similarly (without the benefit of my own exam), I will interpret the stated exam as exhibiting very little muscle spasm, so an injury or infection of the muscle itself is also unlikely.
While a trapezius muscle hernia could conceivably be present, I have never seen one (this is an unusual location). Directly beneath the trapezius are two additional muscle layers, so herniation here would be unusual and would not cause significant morbidity.
The warmth and redness suggest an infectious process. The patient’s underlying eczema predispose her to bacterial skin infections.
I would perform a sono of the mass to determine whether there is pus to drain. Assuming there is no pus, I would change antibiotics to clindamycin, which should be more effective than Augmentin at treating MRSA. I could not find a lot of data on this, but in one study in India, 87% of MRSA were resistant to Augmentin. (Vidhani S et al, Ind J Med Microbiol 2001). I would encourage the family to apply heat to the area to increase blood flow and increase bactericidal activity of white blood cells. Finally, Staph infections can follow an indolent course, then blossom into an overwhelming infection. Therefore, close follow-up with the PCP is required, and a phone call to the PCP should seal this.
The Denouement
by Kaynan Doctor
This patient had elevated WBC of 14.3, CRP (4.3) and ESR (26). Due to the location and the fact that we could not
gauge the depth of this lesion, a neck ultrasound was performed and yielded
images consistent with a large cystic mass.
Official report
Large irregularly shaped fluid collection, in the soft tissues of the right posterior neck. Findings may reflect a large abscess, versus superinfection of a preexisting cystic lesion such as lymphangioma.
Large irregularly shaped fluid collection, in the soft tissues of the right posterior neck. Findings may reflect a large abscess, versus superinfection of a preexisting cystic lesion such as lymphangioma.
ENT was consulted and patient was
admitted to PHAST. Patient subsequently had a CT of the head and neck the next day
which revealed:
Official report
Multiloculated, ill defined fluid collection associated with stranding of the surrounding fat and no definite contrast enhancement. The lesion is located in the subcutaneous region of the right posterior neck and measures about 5 x 3 x 2 cm. There is fat stranding consistent with infiltrative edema crossing the midline to the left. There is no evidence of deep structure extension. There are some normal size lymph nodes in the right occipital chain.
Patient had I&D performed under anesthesia by ENT, straw colored fluid drained. Discharged on 10 day course of clindamycin.
Great case btw. allows a discussion of a relatively simple clinical problem and the different approaches to mgmt.
ReplyDeleteI argue that we should be conscientous for not OVER-TESTING. This is a great situation for a cost analysis. What is the risk for not-draining this fluid collection and seeing if clindamycin outpatient does the trick? We don't drain retropharyngeal abscesses like we used to because the procedure risk is great and they often resolve with IV clinda/unasyn even when loculated or rim-enhancing. The cost of admission and a sedated ENT surgery are significant. I think we're at the era when cost will start driving our decisions and these type of studies would be VERY interesting. I think the patient with high fever and who has failed outpatient antibiotics is a different story....but there is a value chain here where the likelihood x cost for repeat ED visit and ENT drainage may be much less than the cost for immediate drainage.......