Welcome to the second edition of the HipPEMcrates Mailbag – where we continue to explore common questions from the Pediatric Emergency Department. These are the topics that come up during busy shifts, the clinical pearls shared during signout, and the thoughtful questions from learners that prompt us to pause and review the evidence behind our everyday practice.
If you missed our first mailbag, check it out here. As an aside – for those Bill Simmons fans, the mailbag is back! Not saying it’s a response to our first mailbag, but the timing is oddly suspicious. On that note… speaking of things (literally) heating up…
What’s new with 2-3 month old febrile infants – do I need to do bloodwork? A spinal tap?
Every time I give a talk on febrile infants, the question is always raised about what happens once the child hits 2 months of age. If they’re 61 days old, is the risk really that much different than if they’re 58 days? It’s a tricky age group – old enough to not scare people when you see them on the ED track board, but young enough that their immune system is still pretty exposed. Our trustworthy colleagues from PECARN are back with a few great studies looking at bacterial infections in 2-3 month olds.
I’d recommend you go read the papers, but here are some of the highlights:
- Prediction Rule to Identify Febrile Infants 61-90 Days at Low Risk for Invasive Bacterial Infections. Pediatrics. 2025 Sep 1;156(3):e2025071666. doi: 10.1542/peds.2025-071666. PMID: 40854562; PMCID: PMC12432541.
- Study Type: Retrospective cohort study using data from the PECARN Registry
- Objective: To create a clinical prediction rule to identify febrile infants 61-90 days old at low risk for invasive bacterial infections (Bacteremia or Bacterial Meningitis)
- Results:
- N=4952 infants with fever who had a UA/urine dipstick and blood culture sent during initial ED visit
- 2% (n=100) had IBI [95 bacteremia, 5 bacterial meningitis]
- Infants with IBIs were:
- Slightly older
- Higher temperatures
- Higher ANC, PCT, and CRP levels
- Prediction Rules:
- Rule #1 (without PCT and CRP): Infants with negative UA and maximum temperature ≤38.9°C are low risk for IBI
- Sensitivity: 86.0% (95% CI 77.6-92.1)
- Specificity: 58.9% (95% CI 57.5-60.3)
- Rule #2 (with PCT and CRP): Infants with PCT≤0.24 ng/mL and ANC ≤10710 cells/mm3 are low risk for IBI
- Sensitivity: 100% (95% CI 87.2-100)
- Specificity: 65.8% (95% CI 63.0-68.5)
🎥 Dr. Paul Aronson, lead author, explains the study in a brief video
- Risk of Bacterial Infections in Febrile Infants 61 to 90 Days Old With Respiratory Viruses. Pediatrics. 2025 Jul 1;156(1):e2025070617. doi: 10.1542/peds.2025-070617. PMID: 40506050; PMCID: PMC12410455.
- Study Type: Retrospective cohort study using data from the PECARN Registry
- Objective: To describe the prevalence of UTIs, bacteremia, and bacterial meningitis in febrile infants 61-90 days old with and without respiratory viral infections
- Results:
- N=3678 visits (12 infants with 2 visits) with UTI and/or IBI testing, with at least 1 respiratory viral test
- 46.9% with positive respiratory viral test
- Compared with viral-negative infants, respiratory viral-positive infants had a lower prevalence of
- UTIs (4.4% vs 12.5%)
- Bacteremia without meningitis (1.0% vs 3.0%)
- Overall IBI (1.0% vs 3.3%)
- Risk by type of virus
- Proportion of UTIs significantly lower for infants + for COVID, RSV, or flu – compared with those negative for virus
- Prevalence of UTIs similar for + rhinovirus – compared with those negative for virus
- Proportion of bacteremia similar for + vs – RSV or flu
- Prevalence of bacteremia similar for + vs – rhinovirus
- No cases of bacterial meningitis in viral-positive infants
- Take homes:
- Infants with respiratory viral infections had lower prevalence of UTIs and bacteremia vs infants who tested negative
- The presence of UTIs in viral negative infants is non-negligible
🎥 Dr. Paul Aronson, lead author, also explains this study in a brief video
My approach: These findings echo prior studies by PECARN and others that suggest that infants with respiratory viruses are at lower risk for UTIs, bacteremia, and bacterial meningitis. The one caveat – and the thing that gives me some pause in managing these children – is that the risk of bacterial infections, particularly UTIs, is not zero. This is the question that we always consciously (or subconsciously) consider: what level of risk will you tolerate? For a well appearing febrile infant 2-3 month olds with clear viral symptoms, I typically feel comfortable not doing any workup, but make sure to review strict return precautions and recommend pediatrician follow up. For those infants with mild symptoms but persistent fevers, if anything I would consider urine testing – unless they are not well appearing, I don’t typically do bloodwork. If your clinical gestalt is telling you that something else might be going on, do urine and labs – if the inflammatory markers are elevated, can consider LP or can admit off of antibiotics while cultures are pending.
One more bonus article about infants – should you do a set of electrolytes on infants <3 months old with a febrile UTI? Read this article to learn the data.
What do you do?
We see so many viruses, yet parents are always worried about pneumonia. Am I missing something?
It’s time for a quick pediatric pneumonia update. There is a lot of great research on the topic (expert tip: If Todd Florin is on the study, it’s generally an important one), so I am including a definitely-not-exhaustive compilation below to get you started. You should take some time to read the studies, but courtesy of our helpful assistant ChatGPT, here is a concise summary of some of the latest and greatest info about pediatric pneumonia:
Taken together, these studies reshape how we diagnose, risk-stratify, and treat pediatric community-acquired pneumonia. Classic clinical signs and clinician gestalt alone are imperfect predictors of pneumonia diagnosis and severity (JAMA Rational Clinical Examination; Pediatrics—clinician gestalt study), driving increased reliance on validated prediction tools to distinguish mild from moderate or severe disease and guide disposition (PECARN clinical prediction model study; PEM Blog summary). At the same time, evolving epidemiology—highlighted by the resurgence of Mycoplasma pneumoniae—reminds clinicians that not all CAP is typical or bacterial (PEMCurrents Podcast: The Mycoplasma Comeback). On the treatment side, multiple randomized trials consistently show that shorter antibiotic courses—and often lower doses—are noninferior to traditional regimens for most children (SCOUT-CAP; SAFER; CAP-IT). Finally, large outpatient cohort data suggest that select, well appearing children with pneumonia may be safely managed without antibiotics, reinforcing a stewardship-forward, risk-based approach to care (Outpatient Antibiotic Use and Treatment Failure study).
Here’s the compilation:
JAMA Rational Clinical Examination: A systematic review/meta-analysis looking at clinical signs associated with the diagnosis.
Pediatrics: Can clinicians predict severe outcomes from pneumonia with their clinician gestalt?
PEMCurrents Podcast: The Mycoplasma Comeback: Why This Atypical Pneumonia is Back.
PECARN Study: Clinical prediction models to help clinicians distinguish mild from moderate or severe cases of community acquired pneumonia.
- Bonus content: Check out PEMBlog’s post on this study.
SCOUT-CAP Trial: Short- (5-day) vs Standard-Course (10-day) Outpatient Antibiotic Therapy for Community-Acquired Pneumonia in Children.
SAFER Trial: Short-Course Antimicrobial Therapy for Pediatric Community-Acquired Pneumonia.
CAP-IT Trial: Effect of Amoxicillin Dose and Treatment Duration on the Need for Antibiotic Re-treatment in Children With Community-Acquired Pneumonia.
Outpatient Antibiotic Use and Treatment Failure Among Children With Pneumonia: Can some kids with pneumonia be managed without antibiotics?
What’s the future of Pediatric Emergency Medicine?
Ok, well now we are getting serious! I’ve been thinking about this question a lot recently, and you may have seen some chatter about AI on the PEM Listserv. As a slight aside: Over the last few months, I’ve been working with Pediatric Emergency Care journal to interview some of the prominent figures within the field of PEM. We’ve released 2 of the discussions so far – one with THE fathers of the field, Drs. Fleisher & Ludwig, and one with another PEM legend, Dr. Jane Knapp. In these discussions (along with several that will be published in the coming months), it’s been interesting to hear what the OG PEM docs think is to come for pediatric emergency medicine. I will probably make a larger post on this topic at some point, but here are a few of the things that I think will (or will continue to) change our field (and I will caution, I am not an expert on any of these! This is just an ER doc’s random musings. And I haven’t tried most of the products mentioned, so they’re definitely not endorsements):
- AI – Ok, this is the obvious one, and one that is already impacting pretty much every field of every job. AI scribes to reduce time spent on documentation? Clinical alerts learned and continually optimized from the EHR being connected to AI? It’s all already happening! And will likely get better and better. For a really great recent study on what the future holds, check out PECARN’s latest work (and my JournalFeed writeup) on how AI predictive models can use EHR data and predict which children will develop sepsis within 48 hours.
- Virtual Reality – Am I the only one that asks to try the VR goggles every time I am at the Apple Store? We are already using VR as a distraction technique for children during procedures, but I think the area that VR can really impact is helping trainees learn how to do procedures. For example, we do fewer and fewer lumbar punctures (thanks to vaccines!), but how about using VR or AR to practice the procedure – that way, you can know exactly where you are if spinal fluid is not flowing through your needle.
- Telemedicine – Technology is quite amazing these days; we have watches that can take vitals and read heart rhythms, EHR systems that can connect with health systems around the world, and (see #2) VR and AR capabilities that can place the triaging clinicians in the room with the patient and family. Sure, the logistics need to be worked out, but I envision this being the next step of the after-hours pediatrician emergency line. Instead of speaking on the phone and describing what your child looks like to the nurse or physician, it will feel like the clinician is in the room with you, essentially able to see what your child’s work of breathing is or what that rash looks like. The challenge will be the question of who staffs it, who pays for it, and the liability. But if we can figure out how to make it work effectively and efficiently, I can envision this helping to reduce the burden on EDs while also providing better care, especially in medically underserved locations.
That’ll be it for our second mailbag! How did it go? Share your thoughts in the comment section below or send us an email at HipPEMcrates@gmail.com! Do you have a question you’d like answered, share that too! Until next time…
Dr. Joshua Belfer, MD, is a Pediatric Emergency Medicine physician at the Children’s Hospital of Philadelphia, and is the Founder and Editor-in-Chief of HipPEMcrates. He can be reached at HipPEMcrates@gmail.com.
