1/ COVID may have stolen the headlines, but bacteria haven’t gone away. Strep Pneumoniae, Strep Agalactiae (GAS), & Strep Pyogenes (GBS) are as mystifying as ever. Let’s roll our sleeves up & wiz our way through this #StrepTweetorial

#PedsID #PedsHM #MedStudentTwitter

2/ Let’s get started with a case. A bashful 5 yo boy with red hair & 6 siblings presents to his PCP with a fever to 101.2 degF, pain w/ swallowing, & sandpaper-like rash on his chest & upper extremities bilaterally. You don’t need to be a Ravenclaw to figure this one out!

3/ #StrepTweetorialQ1: for the above patient, which answer choice lists the most likely pathogen & antibiotic choice for a patient with NKDA? #StrepTweetorial

4/ B) Scarlet Fever & Strep pharyngitis due to Strep pyogenes (GAS) and treated with low dose amoxicillin (25 mg/kg/dose BID). Azithromycin is an appropriate alternative for penicillin allergy. Strep agalactiae (GBS) infxns are often treated w/ Ampicillin. [1] #StrepTweetorial

5/ #StrepTweetorialQ2 Sadly, this kid had a previous strep infection warranting hospitalization in the first month of life. Which streptococcal species was the most likely to cause of his serious bacterial infection (SBI)?

6/ Answer B is for Babies! [2]

Strep agalactiae: Strep agalactiae (Group B Strep) is a leading cause of SBI in infants. Not to be confused w/ Strep pyogenes (GAS) which causes skin infections & strep throat. #StrepTweetorial

7/ Despite a declining incidence of infection with the initiation of intrapartum prophylaxis to prevent infantile GBS, a disparity remains between white & black children who have 2.4x risk of developing disease. [3] #StrepTweeotiral #EquityInPediatrics

8/ Alrighty, the next case involves a precocious 6 yo daughter of dentists who presents with ear pain but no pain when pulling on the pinna. Her father first noticed a change in her mood a few days prior despite recently winning a national spelling contest. #StrepTweetorial

9/ #StrepTweetorialQ3 On exam, she has an unremarkable external ear, but otoscope reveals effusion with erythematous tympanic membranes. Given her story and physical exam, what is the most likely pathogen? #StrepTweetorial

10/ Streptococcus Pneumoniae [4]

A. Strep pyogenes: oops! See above
B. Pseudomonas: So close. More likely otitis externa
C. Strep agalactiae: GBS has an A, poor naming if you ask me...
D. Not B, not A, but Pneumoniae! Other common bacteria include H. flu & Moraxella catarrhalis

11/ #StrepTweetorialQ4 Unless your medical school had a strong Charms curriculum, you’ll likely need an antibiotic to help this kiddo. Select the appropriate first and second line antibiotic for acute otitis media (AOM). #StrepTweetorial

12/ Answer = C. High dose Amoxicillin is a reasonable first line option; you will need to ensure she has no Hx of penicillin allergy. If there is a Hx of recurrent AOM infections, recent antibiotic use, or evidence of concomitant conjunctivitis, Amox/Clav is a great option! [5]

13/ #StrepTweetorialQ5 Your pt’s friend who attended the same spelling bee (2nd place) presents to his pediatrician as well, but this time with difficulty breathing, cough, & fever. Although stable, his exam is suspicious for a RLL PNA. What is your next step & proposed tx plan?

14/ Answer = C. Amoxicillin is the best kept secret since the Room of Requirement. Not all pneumonia needs to be treated inpatient. Many cases of community acquired PNA, especially in kids >6m do not require hospitalization if clinically stable. [6] #StrepTweetorial

15/ If GAS pharyngitis isn’t adequately tx, post infxn sequelae such as acute rheumatic fever (cue JONES criteria) can be problematic. Risk for post-streptococcal glomerulonephritis isn’t impacted by tx. That’s a story for another . [1] #StrepTweetorial https://www.mdcalc.com/jones-criteria-acute-rheumatic-fever-diagnosis

16/ For GBS infections, there is both early onset disease (0-6 days of life) & late-onset disease (7-89 days of life) with varying symptomatology. Just because they are a few weeks old, doesn’t mean they are out of the woods yet. Good prenatal care is KEY! [3] #StrepTweetorial

17/ Last but not least, strep pneumo vaccines: PCV13 (conjugate) & PPSV23 (polysaccharide). Remember, kids <2 years, folks >65, & smokers are at the greatest risk for pneumococcal infections. Vaccines are safe, powerful, & effective. Sounds like magic. [7] #StrepTweetorial

18/ Shout out to @morg_rice, a med student colleague who co-authored this thread with me. Many thanks to @STangGirdwood for teaching us all about strep infections & showing us the ropes this month on #PedsHM. We hope you enjoyed this #StrepTweetorial #PedsID #MedStudentTwitter

19/ References:
[1] https://pubmed.ncbi.nlm.nih.gov/22965026/ 
[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6439883/
[3] https://pubmed.ncbi.nlm.nih.gov/30640366/ 
[4] https://pubmed.ncbi.nlm.nih.gov/14506123/ 
[5] https://pubmed.ncbi.nlm.nih.gov/23439909/ 
[6] https://pubmed.ncbi.nlm.nih.gov/21880587/ 
[7] https://pubmed.ncbi.nlm.nih.gov/19821336/