Use hospital MRSA rates to guide pediatric osteomyelitis treatment
SEATTLE – If your hospital’s methicillin-resistant Staphylococcus aureus rate is less than 10%, cefazolin is a reasonable empiric choice for pediatric acute hematogenous osteomyelitis (AHO). It covers the usual suspects: methicillin-susceptible Staphylococcus aureus, group A Streptococcus, and Kingella.
Dr. Nivedita Srinivas
Above the 10% mark, coverage should include considerations of MRSA; clindamycin is good option so long as 85% of isolates are susceptible. Above that, it’s time for vancomycin, according to Nivedita Srinivas, MD, a pediatric infectious disease specialist at Stanford (Calif.) University.
There are no practice guidelines in the United States for the diagnosis and management of AHO in children; Dr. Srinivas and colleagues sought to plug the gaps in a talk at Pediatric Hospitalist Medicine.
Pediatric AHO is more common in children under 5 years old and in boys. Lower extremities are the usual targets. Staphylococcus aureus, group B Streptococcus, and gram negatives are the most common causes in newborns; Staphylococcus aureus, group A Streptococcus, and Kingella in older infants and preschoolers; and Staphylococcus aureus and group A Streptococcus in older children.
About half the time, treatment remains empiric because nothing grows out on culture, and there are a few clinical pearls to keep in mind in those cases. A family history of boils or spider bites is suspicious for MRSA, and coverage should include Salmonella in children with abnormal hemoglobins and Streptococcus pneumoniae in children without a spleen or with functional asplenia. Pseudomonas has to be kept in mind with puncture wounds, and Brucella in children who drink unpasteurized milk, Dr. Srinivas said.
Dr. Marie Wang
A switch from IV to oral therapy is appropriate when C-reactive protein (CRP) drops 50% from its peak or below 3 mg/dL, positive cultures – if any – turn negative, fever has been absent for 24 hours, there’s no sign of metastatic disease, and patients have markedly reduced pain and can bear weight on the infected limb, said copresenter Marie Wang, MD, also a pediatric infectious disease specialist at Stanford.
The oral switch, of course, must have similar coverage as the IV antibiotic: high-dose cephalexin for cefazolin, for instance. Children can be sent home on a PICC line to continue IV treatment, but they won’t do any better than children switched to an oral treatment, and the indwelling catheter can cause problems, she said.
Pleuritic or other sudden pain at a distant site suggests septic emboli. “[Staphylococcus aureus] is notorious for going places you don’t” expect it to go “and forming microabscesses, which become larger abscesses” and need to be drained, said the third presenter, Russell McCulloh, MD, a pediatric infectious disease specialist at the University of Nebraska Medical Center, Omaha.
Four weeks of antibiotics are usually enough, so long as there aren’t complications such as septic thrombophlebitis, endocarditis, sickle cell disease, skull involvement, or immunodeficiencies. Source control and good, postdischarge care – including regular CRP and antibiotic toxicity labs – are critical. Monitoring is recommended for a year.
“X-rays are good at looking for longer-term complications, but bony abnormalities are not going to show up for the first 2 weeks,” Dr. McCulloh said.
The presenters didn’t have any relevant disclosures. The meeting was sponsored by the Society of Hospital Medicine, the American Academy of Pediatrics, and the Academic Pediatric Association.
