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September 2003
A 10-year-old girl presented to the local medical center emergency department for evaluation and treatment of right back and flank pain. The onset of her pain was about four days earlier and had since spread around to involve her right upper and right lower quadrants of her abdomen. Using a 10-point pain scale, she described her pain to be in the range of 7 to 8, with minimal response to ibuprofen or changes in position except curling her legs up while in the supine position. Activities such as walking exacerbated the pain. She also complained of some anorexia and nausea, but no vomiting or diarrhea or significant constipation. She denied sexual activity and had not yet had menarche. She also denied dysuria. She had not complained of chills or fever, but her temperature had not been taken at home. Her past medical history is significant for having type 1 diabetes mellitus for about three years, with poor control due to lack of compliance. Her only hospitalization was about one year earlier to treat diabetic ketoacidosis. There is no history of prior urinary tract infections, abdominal surgery or trauma. Her only regular medication is insulin, although she occasionally takes a stool softener. Her family and social history is unremarkable, and her immunizations are up to date, and there has been no recent travel or animal exposure. Examination revealed a normal-appearing 10-year-old female with normal vital signs and mild distress due to pain. Her positive findings centered about the right abdomen and flank with pain on deep palpation. There was mild costovertebral angle (CVA) tenderness on percussion. There was no abdominal rebound pain nor pain along the spinous processes. She had a negative psoas sign when tested. The rectal and pelvic exam was normal. Lab tests included serum electrolytes, liver enzymes, and a complete blood count revealing only an elevated glucose of 403. Her urinalysis revealed only trace ketones, and was otherwise normal. Her chest and abdominal radiographs were normal. Her abdominal CAT scan is shown in figure 1 & 2.
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The computed tomography (CT) scan reveals the correct answer — a right-sided renal abscess (A), a relatively uncommon condition in children. The lesion measured 7 cm x 5 cm x 7 cm with a hypodense center. Approximately 30 cc of purulent fluid was aspirated under CT-guidance and an 8 French “pigtail” catheter was left in place. Gram’s stain revealed gram-negative rods, and the culture gew Klebsiella pneumoniae.
These abscesses can be the result of bacteremic seeding (primary renal abscess) or extension of pyelonephritis (secondary renal abscess). If due to bacteremia, the most common organism is Staphylococcus aureus with streptococcus being second. When the abscess occurs as a result of a complication of pyelonephritis the most likely organisms would include Escherichia coli and other Gram-negatives. With this patient’s normal UA, and negative past medical history of previous urinary tract infections, one would have expected a gram-positive coccus. However, this is a good example of why initial therapy in cases like this should include coverage for both scenarios. I think a good combination would be gentamicin plus extended-spectrum penicillin or a third-generation cephalosporin. The aminoglycoside can be given once a day, and if ceftriaxone (Rocephin, Roche) is chosen this can also be given once a day. However, ceftriaxone is not as concentrated in the urinary system as the other third-generation cephalosporins, but for all practical purposes, it probably does not need to be. Depending of the situation, one might want to consult an infectious disease specialist for a case like this. Regardless of the etiology, drainage of the abscess is most important, both for diagnosis and therapy.
Diskitis may present with similar symptoms, and can be seen in children this age, although it is more common in younger children. The presenting pain with diskitis depends on the level of involvement. It is not unusual for patients to complain of vague back and/or abdominal pain with thoracic or lumbar diskitis. There is often a history of some injury. Even minor injuries may set the stage for diskitis. The most common organism recovered is also S. aureus, although a variety of other organisms have been recovered. In most cases, no attempt is made to recover an organism, but rather to put the patient to rest and give an anti-staph antibiotic for some time depending on the clinical response. Most cases of diskitis are simple to treat, but in some cases, vertebral osteomyelitis may complicate the infection (figure 3). This is obviously a more serious problem, needing the attention of an orthopedic surgeon. And again, an infectious disease specialist may also be helpful.
A psoas muscle abscess can also present with vague symptoms like this patient had. This condition is often associated with some underlying bowel problem like inflammatory bowel disease or appendicitis. It can also be associated with UTIs, but in some cases, it results from bacteremic seeding. The organisms recovered are similar to those mentioned above, depending on the underlying cause. Also, do not rely on a negative “Psoas Sign” to rule out a psoas abscess. The patient in figure 4 was initially thought to have a septic hip with a negative Psoas sign. Her psoas abscess grew S. aureus.
It is noteworthy that the patient presented above had a history of insulin-dependent diabetes mellitus that was poorly controlled. Over time, this can have a deleterious effect on the immune system, mostly with the cellular function, setting the patient up for unusual and/or severe infections. The patient, especially adults, can have severe staph infections, malignant otitis externa, and invasive fungal infections such as rhinocerebral mucormycosis. Also, renal abscesses are seen more frequently in diabetic patients, especially adults. So, expect the unexpected with diabetic patients.
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A P.S. from Dr. Brien: |
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The worlds of journalism, broadcasting and politics lost a legendary pioneer on July 29th. John Reagan (Tex) McCrary died in New York at the age of 92 years. What does Tex McCrary's passing have to do with pediatric infectious diseases? Probably nothing directly. However, Tex quietly influenced so many things, I wouldn't be surprised if there were a connection. My connection with Tex is that he was born and raised in Calvert, Texas, which also happens to be the hometown in which my wife and I grew up. Her parents grew up with and knew Tex and his family well. I would refer you to the obituary sections of any number of major newspapers from the 30th-31st of July, or to a good search engine like Google.com, for details of his life and accomplishments. The best write-up I found was in The New York Times, complete with a picture of Tex and his second wife, Jinx Falkenburg, with whom he produced one of the first TV and radio talk shows. The last time I saw Tex McCrary was several years ago on a visit to New York where our daughter now lives (picture of Tex, my wife Ellen, daughter Amber and myself).
You may begin to wonder if there's something in the water in Calvert to have such an array of success (or at least notorious) stories come from such a small town. Well, it's not without tragedy. In the summer of 1873, a yellow fever epidemic wiped out over one-third of the population and probably contributed to the economic deterioration of the community from which it never fully recovered. This is also a part of Calvert history that fascinates me. In fact, the yellow fever story in the United States, especially the Southern states, is a fascinating story to revisit. Perhaps we will have a column on this topic, even though we don't see endemic yellow fever in the United States anymore. This is obviously a tribute to the people in our Public Health System, often unrecognized for the work they do. They are sort of like vaccines. You don't really know how well they work until you stop using them. So, the Tex McCrary connection to an infectious diseases column is that his parents, who also grew up in Calvert, survived the yellow fever epidemic of 1873. |
Acknowledgement: We would like to thank Dr. Susan D. John, MD, of The University of Texas Health Science Center in Houston, Department of Radiology, for assisting with the case and contributing figures 1 and 2.
For more information:
- Yen, et al. Renal abscess: early diagnosis and treatment. Amer J Emerg Med. 17(2):
193-197.- Gonzales, Edmond Jr., Chapter 47 in Feigin and Cherry’s 4th Edition Textbook of Pediatric Infectious Diseases.
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Almost
everyone learns unique facts about their hometown, and I am no different. For
example, Calvert, Texas, which now has a population of about 1,000 people, was
once an old-fashioned Western “boom town,” fed by cotton, cattle and
one of the first rail lines in Texas. In addition to producing a famous outlaw
(Belle Starr), Calvert made Ripley's Believe It or Not by
producing three Navy Admirals in World War II. The nearest shore is the Gulf of
Mexico, about 200 miles away. In more modern times, a Calvert native went on to
become one of the first black mayors of a major city, Mayor Tom Bradley of Los
Angeles. A federal judge and former deputy attorney general of the United
States, Tyree Sneed, nominated by Richard Nixon in 1973, also grew up in
Calvert. Judge Sneed is also the father of Carly (Carleton) S. Fiorina, the CEO
of Hewlett-Packard. Ms. Fiorina did not grow up in Calvert, but the connection
must have helped.