Modern EM: Case 1 and 2 - Strep Throat

A sister and brother, aged 7 and 14, respectively present with pharyngitis.  The 7F has sore throat, cough, fever, and post-tussive vomiting for 1 day.  She has posterior pharyngeal erythema, no lymphadenopathy, no exudate, no petechiae, and looks like a viral URI.

The 14M had culture confirmed GAS pharyngitis 3 weeks ago, was treated with PCN-VK and symptoms resolved.  Now, he's in the ED with signs and symptoms of pharyngitis again, including dysphagia, fever, cough, posterior pharyngeal erythema, swollen tonsils, LAD, and petechiae on his hard palate.

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I ordered cultures on each of them and then I opened up MDCalc (I have shortcuts saved to all my devices' desktops) to the Modified Centor Score for Strep Pharyngitis.  The easy-to-use calculator tells me that I won't treat the 7F unless positive cultures come back, and the 14M will get empirically covered.

But what antibiotic do I give him?  It seems that he failed PCN-VK.  Traditionally, many have reached for azithromycin next but I had just read a plea by Dr. Ryan Radecki on his blog EM Literature of Note to stop using macrolides for strep throat based on a study out of Rush that reported cases of rheumatic fever secondary to macrolide resistance.  The paper also notes as high as a 15% US single center resistance rates.

If not a z-pack, then what?  I opened the EMRA Abx guide which recommended cephalexin or clindamycin.  I chose cephalexin, rechecked in Micromedix the indications and dosing, and felt confident I had made the right choice.  I also noted to myself that if in the future I were treating a child with a history of PCN anaphylaxis, then clindamycin would be my choice.