Girl, 5, With Fever and Hip Pain

A 5-year-old Filipino girl was brought to a pediatric clinic for follow up of an unresolved fever and for new-onset right hip pain, which occurred intermittently for the past week and was associated with a right-sided limp. She had been experiencing nightly fevers ranging from 101°F to 105°F for the past two weeks, for which her parents had been giving ibuprofen with mixed results; she remained afebrile during daytime hours.

Using the Wong-Baker FACES pain scale, the patient rated the pain as a 4/10 in severity (“Hurts a Little More” face).¹ Standing and walking aggravated the pain but did not limit activity. Although ibuprofen decreased the fever, it did not alleviate the hip pain. Other symptoms included vomiting one to two times daily, without hematemesis, and four to five episodes of diarrhea daily, without abdominal pain, hematochezia, or melena. She also experienced decreased appetite, but her parents reported no change in her dietary or fluid intake. The patient and her parents denied additional symptoms.

Further investigation revealed that the patient had been seen a week earlier by two other clinicians in the office for complaints of fever, rash, nausea, hematemesis, and diarrhea. She had been diagnosed with a herpes simplex viral (HSV) lesion of the nose, epistaxis, and viral gastroenteritis. Her treatment plan consisted of acyclovir ointment for the HSV lesion and symptomatic support for the ­gastroenteritis associated diarrhea. The complaint of hematemesis was attributed to postnasal drip from the epistaxis, and reassurance was provided to the patient and family. In addition, six weeks earlier, the patient had been treated for otitis media with a full course of amoxicillin.

Medical history was negative for surgeries, trauma, injuries, and chronic medical conditions. She took no medications or supplements on a regular basis. Her parents denied any known drug allergies and stated that her immunizations were up to date.

The patient lived at home with her biological parents and two brothers, all of whom were healthy, without any recent infections or illnesses. Of significance, the family had travelled to the Philippines for vacation about four months earlier. Results of a tuberculin skin test done six weeks earlier (because the patient presented with respiratory symptoms shortly after traveling to the Philippines) were negative.

Physical examination revealed a well-developed, well-nourished 40-lb girl, in no acute distress, who was active and playful with her brother while in the exam room. Vital signs were significant for a fever of 101.9°F (last dose of ibuprofen was approximately six hours earlier) but were otherwise stable. Skin exam revealed that the prior HSV lesion of the nose had resolved. HEENT, cardiovascular, and pulmonary exam findings were noncontributory. Urine dipstick was negative.

Abdominal exam revealed normoactive bowel sounds in all four quadrants, and on palpation, the abdomen was soft, nontender, and without organomegaly. Specialized abdominal exams to assess for peritonitis, including those to elicit Rovsing, rebound tenderness, obturator, and psoas signs, were all negative. Bilateral extremity exams of the hips, knees, and ankles revealed full range of motion (active and passive), with normal muscle strength throughout. The only significant finding on the physical exam was mild pain of the right anterior hip at 15° of flexion, appreciated while the patient was supine on the exam table. The patient was also observed pushing off her right lower extremity when climbing onto the exam table, and she skipped down the hall when leaving the exam.

With fever of unknown origin (FUO) and a largely negative history and physical, the working list of differential diagnoses included
• Avascular necrosis
• Bacteremia
• Juvenile idiopathic arthritis
• Osteomyelitis
• Pyelonephritis
• Reiter syndrome
• Rheumatic fever
• Rheumatoid arthritis
• Septic joint
• Urinary tract infection

To begin the diagnostic process, a number of laboratory tests and imaging procedures were ordered. Table 1 presents the results of these studies. A tuberculin skin test was not repeated. While awaiting test results, the patient was started on naproxen oral suspension (125 mg/5 mL; 4 mL bid) for fever and pain control.

Based on findings consistent with an inflammatory pattern, the history of otitis media (of possible streptococcal origin) six weeks prior to this visit, and the elevated ASO titer, the patient was started on penicillin V (250 mg bid) and instructed to return for follow up in two days.

At the follow-up visit, no improvement was noted; the patient continued to experience nightly fevers and hip pain. Rovsing, rebound tenderness, obturator, and psoas signs continued to be negative. Physical examination did, however, reveal a mild abdominal tenderness in the right lower quadrant.

Due to this new finding, an abdominal ultrasound was ordered to screen for appendicitis. Despite the parents’ appropriate concern for the child, misunderstanding about the urgent need to obtain the abdominal ultrasound led to a two-day delay in scheduling the exam. Results of ultrasonography revealed psoas abscess, and the patient was promptly admitted to the pediatric floor of the local hospital.

Continue for discussion >>