My 10-year-old daughter started complaining of hip pain and spiked a temp. We took her to the pediatrician who took an X-ray and did some lab studies. The X-ray didn’t show anything so an MRI was ordered. The MRI didn’t show anything either but the lab tests were positive for some type of infection. Should we have a second MRI done before putting her on antibiotics?

Antibiotics are still the first line of treatment for bacterial infections. The overuse of antibiotics for all infections, including viral infections, which aren’t affected by antibiotics has led to antibiotic-resistant bacteria. Doctors are much more careful now in prescribing these drugs.

Joint infection frequently does not show up on X-rays. It may not be apparent on early MRIs either. Studies show that MRIs done after six days of symptoms are more likely to be positive when there is a joint infection than MRIs taken in the first six days.

If the lab tests show elevated white blood cells (WBCs), increased sed rate, and increased C-reactive protein, then treatment can proceed. If there’s any doubt, a second MRI can be done after six days. Depending on which joint is a problem, the doctor can also remove a little fluid from the joint and test it. This will identify the specific organism causing the infection.

You are safe to follow your pediatrician’s advice in treating this problem with an antibiotic.