Pediatrics (System-Integrated)

Pediatric pharyngitis: streptococcal vs viral

Clinical Overview and When to Suspect Streptococcal Pharyngitis

— Viral causes dominate overall (~70–80%): rhinovirus, adenovirus, coronavirus, influenza, parainfluenza, RSV, EBV, enterovirus, HSV

— Group A Streptococcus (GAS, S. pyogenes) causes 20–30% of pediatric pharyngitis ages 5–15

— GAS is rare under age 3 (<10–14%); suppurative and nonsuppurative complications are also uncommon in this group

— Acute sore throat without cough, coryza, conjunctivitis, hoarseness, or oral ulcers

— Fever ≥38°C, tender anterior cervical lymphadenopathy, tonsillar exudates, palatal petechiae

— Sudden onset, school-age child, sick contact at home or school, late winter/early spring

— Headache, abdominal pain, nausea/vomiting (especially in younger children)

— Conjunctivitis, rhinorrhea, cough, diarrhea, viral exanthem, discrete oral ulcers, hoarseness

— Posterior cervical lymphadenopathy with hepatosplenomegaly suggests EBV

— Untreated GAS → acute rheumatic fever (ARF), peritonsillar abscess, scarlet fever, post-streptococcal glomerulonephritis (PSGN)

— Overtreatment → antibiotic resistance, C. difficile, allergic reactions, cost

— Antibiotics do not prevent PSGN, only ARF — a frequent distractor

Board pearl: In a child <3 years, do not routinely test or treat for GAS unless there is a sick household contact with confirmed strep — the pretest probability is too low and ARF essentially does not occur in this age group. Focus instead on supportive care and considering alternative diagnoses such as adenovirus or herpangina.

Pediatric pharyngitis is one of the most common ambulatory complaints in children ages 3–15, accounting for ~12 million US visits annually.

Etiology distribution by age:

When to suspect GAS specifically:

When viral etiology is more likely:

Why it matters on Step 3:

Presentation Patterns and Key History

— Abrupt sore throat, odynophagia, fever 38.3–40°C

— Headache, abdominal pain, nausea, vomiting — disproportionately common in school-age kids

— Absence of upper respiratory viral symptoms

— Sandpaper-textured rash + circumoral pallor + strawberry tongue = scarlet fever (pathognomonic for GAS exotoxin)

— Gradual onset, low-grade fever, prominent cough, rhinorrhea, hoarseness, conjunctivitis

— Adenovirus: pharyngoconjunctival fever, high fevers, exudates that mimic GAS

— Coxsackie A (herpangina): small vesicles/ulcers on soft palate and tonsillar pillars; hand-foot-mouth disease adds palmar/plantar lesions

— HSV gingivostomatitis: anterior mouth ulcers, gingival involvement, drooling in toddlers

— EBV (infectious mononucleosis): adolescent, prolonged fatigue, posterior cervical lymphadenopathy, hepatosplenomegaly, palatal petechiae, exudative tonsillitis

— Acute retroviral syndrome (HIV): mono-like illness with rash, mucocutaneous ulcers — ask sexual history in adolescents

— Sick contacts, daycare/school outbreaks

— Immunization status (consider diphtheria in unvaccinated immigrants)

— Sexual history in adolescents (gonococcal pharyngitis)

— Prior episodes of pharyngitis, history of rheumatic fever, recurrent tonsillitis

— Sleep-disordered breathing, snoring (tonsillar hypertrophy consideration)

— Allergies, especially penicillin

Step 3 management: Use the Centor or McIsaac criteria to structure your history-physical synthesis in school-aged children: (1) fever >38°C, (2) absence of cough, (3) tender anterior cervical adenopathy, (4) tonsillar exudate/swelling, plus age adjustment (+1 for age 3–14, 0 for 15–44, −1 for ≥45). A score ≤1 essentially excludes GAS and no testing is indicated; testing is reserved for scores ≥2.

Classic GAS presentation ("strep throat"):

Viral pharyngitis clues:

Key history elements to elicit:

Physical Exam Findings and Severity Assessment

— Fever pattern, tachycardia out of proportion to fever may suggest dehydration or systemic illness

— Assess hydration: capillary refill, mucous membranes, tear production, urine output

— Respiratory distress, stridor, drooling, tripoding → airway emergency (epiglottitis, retropharyngeal/peritonsillar abscess)

— GAS clues: erythematous tonsils with white-yellow exudate, palatal petechiae, beefy-red uvula, enlarged tender anterior cervical nodes

— Scarlet fever: strawberry tongue (white coating then red papillae), circumoral pallor, sandpaper rash in flexural areas with Pastia lines

— Viral clues: vesicles, discrete ulcers (herpangina, HSV), conjunctival injection (adenovirus)

— EBV: massive symmetric tonsillar hypertrophy with grey-white exudates, palatal petechiae, posterior cervical lymphadenopathy, splenomegaly

— Trismus + muffled "hot potato" voice + uvular deviation → peritonsillar abscess

— Torticollis + neck stiffness + drooling in young child → retropharyngeal abscess

— Stridor, severe pain out of proportion → epiglottitis (rare post-Hib vaccine)

— Unilateral neck swelling with septic appearance → Lemierre syndrome (Fusobacterium)

— Sandpaper rash → scarlet fever

— Maculopapular rash after amoxicillin → highly suggestive of EBV (not true penicillin allergy)

— Vesicles on palms/soles → hand-foot-mouth

Key distinction: Anterior cervical lymphadenopathy with exudative tonsillitis fits GAS; posterior cervical lymphadenopathy with hepatosplenomegaly fits EBV. A child with these latter findings should have a heterophile (Monospot) or EBV serologies, and should avoid contact sports for 3–4 weeks to prevent splenic rupture.

Vital signs:

Oropharyngeal exam:

Red flags requiring urgent action:

Skin exam:

Diagnostic Workup — Initial Testing

— Patients with clear viral features (cough, coryza, conjunctivitis, ulcers, hoarseness) → no testing, no antibiotics

— Patients with features suggestive of GAS → rapid antigen detection test (RADT) ± throat culture

— Sensitivity 70–90%, specificity ~95%

— Positive RADT in a child with compatible symptoms → treat for GAS (no culture needed)

— Negative RADT in a child → back-up throat culture is recommended per IDSA/AAP because of imperfect sensitivity and the high consequences of missed GAS (rheumatic fever risk)

— In adolescents/adults, back-up culture is not routinely required due to lower ARF risk

— Gold standard, sensitivity 90–95%; results in 24–48h

— Proper technique: swab both tonsils and posterior pharynx, avoid tongue/cheek

— Increasing availability; sensitivity/specificity >95%

— Acceptable as standalone if validated; no back-up culture needed

— Children <3 years routinely (low GAS prevalence, no ARF risk)

— Asymptomatic carriers (10–20% of school children carry GAS); testing siblings/contacts is generally not indicated

— Recently treated patients (post-treatment "test of cure" is not recommended)

— CBC, heterophile antibody, EBV VCA IgM if mononucleosis suspected

— Atypical lymphocytes >10% supports EBV

Board pearl: A child with sore throat and a maculopapular rash after receiving amoxicillin — order heterophile antibody or EBV serology, not penicillin allergy testing. The rash is an immune-mediated reaction in EBV, not true IgE-mediated penicillin allergy.

Do not test all sore throats. Selective testing based on clinical probability reduces overdiagnosis.

IDSA/AAP recommended approach for ages ≥3:

Rapid antigen detection test (RADT):

Throat culture:

Nucleic acid amplification tests (NAAT/PCR):

Avoid testing:

Additional labs only if alternative diagnosis suspected:

Diagnostic Workup — Advanced or Confirmatory Studies

— Repeat exam for missed peritonsillar/retropharyngeal abscess

— Consider EBV serology (heterophile may be falsely negative in children <4 years — use VCA IgM/IgG, EBNA)

— CMV serology in heterophile-negative mono-like illness

— HIV RNA PCR in adolescents with mono-like syndrome and risk factors (acute HIV antibody may be negative in window period)

— Gonococcal NAAT of pharynx in sexually active adolescents

— Peritonsillar abscess: clinical diagnosis, but CT neck with contrast if uncertain or to distinguish cellulitis vs abscess

— Retropharyngeal abscess: lateral neck radiograph (prevertebral soft tissue widening) → confirm with contrast CT neck

— Lemierre syndrome: CT neck with contrast showing internal jugular vein thrombosis; blood cultures for Fusobacterium necrophorum

— ASO and anti-DNase B titers (anti-DNase B more sensitive in children)

— ECG (PR prolongation), echocardiogram (valvulitis — mitral most common)

— ESR, CRP elevated

— Apply Jones criteria (revised 2015)

— Urinalysis: hematuria, RBC casts, mild proteinuria

— Complement: low C3, normal C4

— ASO/anti-DNase B titers (anti-DNase B for skin source)

— BMP for renal function, BP

— Document episodes; refer ENT per Paradise criteria

Step 3 management: A child 2 weeks post-pharyngitis with tea-colored urine, periorbital edema, and hypertension — order UA, BMP, C3, ASO/anti-DNase B. Management is supportive (salt/fluid restriction, loop diuretics for volume overload, BP control); antibiotics do not change PSGN course but treat any persistent GAS.

When initial testing is ambiguous or complications suspected, escalate workup:

Persistent symptoms despite negative GAS testing:

Suspected suppurative complication:

Suspected rheumatic fever (weeks after pharyngitis):

Suspected PSGN (1–3 weeks post-pharyngitis or impetigo):

Recurrent tonsillitis evaluation:

Risk Stratification and Management Logic

— Score 0–1 (Centor/McIsaac): no testing, no antibiotics, symptomatic care

— Score 2–3: test with RADT (+ back-up culture if negative in children)

— Score 4–5: test; empiric treatment not recommended per IDSA — testing remains standard

— Positive RADT or throat culture or NAAT

— Clinical scarlet fever with high pretest probability (some clinicians treat empirically)

— Documented exposure to a household member with confirmed GAS plus symptoms

— Prevent acute rheumatic fever (within 9 days of symptom onset is effective)

— Shorten symptom duration (~1 day)

— Reduce transmission (noninfectious after 12–24h of effective therapy)

— Prevent suppurative complications (peritonsillar abscess, mastoiditis)

— Does NOT prevent PSGN — frequently tested

— After 24 hours of effective antibiotics and afebrile

— Acetaminophen or ibuprofen for pain/fever (ibuprofen often superior for throat pain)

— Adequate hydration, cold/soft foods, saltwater gargles in older children, throat lozenges (>4 years to avoid choking)

— Avoid aspirin in children (Reye syndrome)

— Honey for cough in children >1 year

— Corticosteroids: single-dose dexamethasone may modestly reduce severe pain but not routinely recommended in uncomplicated pediatric pharyngitis

— Chronic GAS carriers test positive but have viral illnesses; do not transmit ARF risk

— Treatment of carriers generally not indicated except in specific scenarios (family history of ARF, outbreak)

Board pearl: Antibiotics started within 9 days of symptom onset still effectively prevent rheumatic fever — there is no rush to treat empirically before culture results return in low-to-moderate probability cases.

Decision framework drives both testing and treatment:

Treat GAS pharyngitis when:

Goals of antibiotic therapy (important board distinction):

Return-to-school:

Symptomatic management for all causes:

Carriers vs active infection:

Pharmacotherapy — First-Line Antibiotic Regimens

— Penicillin V oral: children 250 mg BID-TID (or 500 mg BID for >27 kg) × 10 days

— Amoxicillin oral: 50 mg/kg/day once daily (max 1000 mg) × 10 days — preferred in pediatrics for palatability and once-daily dosing

— Alternative: amoxicillin 25 mg/kg BID × 10 days

— Benzathine penicillin G IM single dose (600,000 U if <27 kg; 1.2 million U if ≥27 kg) — useful for adherence concerns, vomiting, or rheumatic fever prophylaxis

— Non-severe (delayed, non-anaphylactic) reaction: cephalexin 40 mg/kg/day divided BID (max 500 mg/dose) × 10 days, or cefadroxil 30 mg/kg once daily

— Severe/IgE-mediated (anaphylaxis, angioedema, SJS/TEN): avoid all beta-lactams →

▪ Clindamycin 7 mg/kg/dose TID (max 300 mg/dose) × 10 days

▪ Azithromycin 12 mg/kg once daily (max 500 mg) × 5 days

▪ Clarithromycin 7.5 mg/kg BID × 10 days

— Macrolide resistance rates 5–15% in US; check local antibiogram

— Trimethoprim-sulfamethoxazole and tetracyclines — do not reliably eradicate GAS

— Fluoroquinolones — pediatric concerns and overly broad

— Most are reinfection or carriage with intercurrent viral illness

— Consider clindamycin or amoxicillin-clavulanate for true recurrent GAS within weeks (beta-lactamase from oral flora theoretically protects GAS)

— Tonsillectomy reserved for Paradise criteria

Step 3 management: A 7-year-old with culture-proven GAS pharyngitis and a history of amoxicillin-induced hives — prescribe cephalexin (cross-reactivity <2% with non-anaphylactic reactions) or clindamycin/azithromycin if you cannot exclude anaphylaxis.

First-line: Penicillin or amoxicillin (narrow spectrum, cheap, never reported GAS resistance):

Why 10 days? Shorter courses have higher GAS eradication failure and higher ARF risk; full 10-day course required for ARF prevention even after symptoms resolve.

Penicillin allergy management:

Avoid:

Treatment failures or recurrences:

Adjunctive Management and Procedural Considerations

— Ibuprofen 10 mg/kg q6–8h (max 40 mg/kg/day) — superior to acetaminophen for throat pain in trials

— Acetaminophen 15 mg/kg q4–6h (max 75 mg/kg/day)

— Topical anesthetic sprays/lozenges in older children; benzocaine carries methemoglobinemia risk in young children — avoid <2 years

— Single-dose dexamethasone 0.6 mg/kg PO (max 10 mg) may be considered for severe odynophagia limiting oral intake, but not routine

— Encourage cold fluids, popsicles, soft foods

— IV fluids if poor oral intake → dehydration; admit for inability to tolerate antibiotics or fluids

— Peritonsillar abscess:

▪ Needle aspiration or incision and drainage (ENT consult)

▪ Ampicillin-sulbactam IV or amoxicillin-clavulanate PO; add clindamycin if MRSA risk

▪ Single-dose IV dexamethasone reduces pain

— Retropharyngeal abscess:

▪ Airway protection priority; ENT consult for surgical drainage if large or compromising airway

▪ IV ampicillin-sulbactam or clindamycin

— Lemierre syndrome:

▪ Prolonged IV antibiotics (ampicillin-sulbactam, piperacillin-tazobactam, or carbapenem) for 3–6 weeks

▪ Anticoagulation controversial — case by case

— Recurrent tonsillitis — tonsillectomy referral (Paradise criteria):

▪ ≥7 episodes in 1 year, OR

▪ ≥5 episodes/year × 2 years, OR

▪ ≥3 episodes/year × 3 years

▪ Each episode must be documented with fever >38.3°C, exudate, adenopathy, or positive GAS test

CCS pearl: In a CCS case of pediatric peritonsillar abscess, sequence: (1) assess airway, (2) IV access + IV fluids, (3) IV ampicillin-sulbactam, (4) ENT consult for drainage, (5) IV dexamethasone, (6) advance clock 4–6 hours, (7) reassess pain/intake, (8) transition to PO amoxicillin-clavulanate × 10–14 days total.

Supportive pharmacology:

Hydration:

Procedural management by complication:

Sleep-disordered breathing/OSA with tonsillar hypertrophy → polysomnography → adenotonsillectomy

Special Populations — Hepatic, Renal, and Comorbidity Considerations

— Amoxicillin and penicillin are renally cleared — dose adjustment needed for CrCl <30 mL/min:

▪ Amoxicillin: extend interval to q12h (CrCl 10–30) or q24h (<10)

— Cephalexin: reduce dose with CrCl <50

— Clindamycin: minimal renal adjustment needed

— Azithromycin: no renal adjustment

— Azithromycin and clindamycin are hepatically metabolized — use cautiously

— Monitor for cholestatic injury with macrolides

— Acetaminophen dosing reduced; avoid in significant liver disease

— Secondary prophylaxis mandatory:

▪ Benzathine penicillin G IM every 4 weeks (every 3 weeks in high-risk regions or breakthrough cases)

▪ Alternative: penicillin V 250 mg BID PO, sulfadiazine, or macrolide

— Duration:

▪ ARF without carditis: 5 years or until age 21 (whichever longer)

▪ ARF with carditis, no residual valve disease: 10 years or until age 21

▪ ARF with persistent valve disease: 10 years or until age 40, sometimes lifelong

— Continue prophylaxis during any subsequent GAS-suspicious illness with additional treatment dose

— Lower threshold for testing and broader workup

— Consider hospitalization if febrile neutropenia coexists

— Atypical organisms (CMV, candida, anaerobes) more likely

— Prophylaxis for endocarditis is not indicated for routine pharyngitis treatment

— Treat documented GAS promptly to prevent ARF recurrence

— Higher risk of invasive bacterial infections; consider broader workup if febrile and ill-appearing

Board pearl: A 12-year-old with prior rheumatic carditis develops GAS pharyngitis — give a full 10-day treatment course even if on monthly benzathine prophylaxis; the prophylactic dose is insufficient to treat active infection.

Children with renal impairment:

Children with hepatic impairment:

Children with history of rheumatic fever:

Immunocompromised children (chemotherapy, transplant, primary immunodeficiency):

Children with cardiac valvular disease:

Sickle cell disease:

Special Populations — Neonates, Toddlers, and Adolescents

— GAS pharyngitis is extraordinarily rare

— Fever in this age group → full sepsis workup (blood, urine, CSF), not throat swab

— Consider neonatal HSV if oral lesions

— GAS prevalence low; ARF does not occur

— "Streptococcosis" can occur: low-grade fever, nasal discharge, anterior cervical lymphadenitis, irritability — testing/treatment only if household contact with documented GAS

— Major causes: adenovirus, herpangina (coxsackie), HSV gingivostomatitis

— HSV gingivostomatitis treatment: oral acyclovir if presenting within 72–96 hours improves duration; supportive care otherwise; ensure hydration

— Peak age for GAS and ARF

— Apply Centor/McIsaac with age adjustment

— Full 10-day antibiotic course critical

— Mononucleosis (EBV) prominent — counsel on avoiding contact sports/heavy lifting for 3–4 weeks due to splenic rupture risk

— Consider gonococcal pharyngitis: sexually active, treat with ceftriaxone 500 mg IM (1 g if ≥150 kg) per CDC 2021

— Acute HIV in mono-like syndrome → HIV RNA PCR

— Diphtheria in unvaccinated immigrants from endemic regions: grey pseudomembrane, bull-neck, myocarditis risk → diphtheria antitoxin + erythromycin/penicillin, public health reporting

— Penicillin, amoxicillin, cephalexin safe (category B)

— Avoid tetracyclines, fluoroquinolones, and use macrolides cautiously (clarithromycin avoided; azithromycin acceptable)

— Routine screening of asymptomatic contacts not recommended

— Treat symptomatic contacts based on testing

— Notify daycare for hand hygiene measures

Key distinction: A toddler with high fever, exudative pharyngitis, and conjunctivitis most likely has adenovirus (pharyngoconjunctival fever) — supportive care only. A school-age child with the same throat findings but no conjunctivitis warrants GAS testing.

Neonates and infants <3 months:

Children <3 years (toddlers):

Preschool and school-age (3–15 years):

Adolescents:

Pregnant adolescents:

Daycare/school outbreaks:

Complications and Adverse Outcomes

— Peritonsillar abscess (quinsy): trismus, muffled "hot potato" voice, uvular deviation, severe unilateral pain

— Retropharyngeal abscess: torticollis, neck stiffness, drooling, more common in <5 years

— Cervical lymphadenitis with suppuration

— Otitis media, sinusitis, mastoiditis

— Lemierre syndrome: septic thrombophlebitis of internal jugular vein with septic pulmonary emboli; Fusobacterium necrophorum; adolescents/young adults; mortality ~5%

— Bacteremia, sepsis, toxic shock syndrome (rare but life-threatening): GAS produces pyrogenic exotoxins; fever, hypotension, multiorgan dysfunction, erythroderma

— Necrotizing fasciitis — extremely rare from pharyngeal source

— Acute rheumatic fever (ARF): 2–4 weeks post-pharyngitis

▪ Jones criteria: major (carditis, polyarthritis, chorea, erythema marginatum, subcutaneous nodules) + minor (fever, arthralgia, elevated ESR/CRP, prolonged PR)

▪ Evidence of antecedent GAS (ASO, anti-DNase B, recent positive culture)

▪ Antibiotics prevent ARF if started within 9 days

— Post-streptococcal glomerulonephritis (PSGN): 1–3 weeks post-pharyngitis (or 3–6 weeks post-impetigo)

▪ Hematuria, RBC casts, edema, hypertension, low C3

▪ Antibiotics do NOT prevent PSGN — major board point

▪ Generally self-limited in children with good prognosis

— PANDAS (Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcus): controversial; abrupt OCD/tics post-GAS

— Scarlet fever: not really a complication but a manifestation of GAS with erythrogenic toxin

— Reactive arthritis (post-streptococcal): joint inflammation without full Jones criteria

— EBV: splenic rupture, airway obstruction, hemolytic anemia, thrombocytopenia

— Adenovirus: keratoconjunctivitis, myocarditis (rare), hemorrhagic cystitis

Board pearl: ARF is preventable with timely antibiotics; PSGN is not. Memorize this exact phrasing — it appears in nearly every Step 3 strep pharyngitis question that tests pathophysiology of complications.

Suppurative complications (early, days–2 weeks):

Nonsuppurative complications (immune-mediated, late):

Viral complications:

When to Escalate Care — Inpatient, ICU, or Subspecialty

— Airway compromise: stridor, drooling, tripoding, severe trismus

— Suspected epiglottitis (rare post-Hib): keep child calm, do NOT examine throat aggressively, immediate anesthesia/ENT for airway in OR

— Peritonsillar or retropharyngeal abscess (drainage)

— Severe dehydration with inability to tolerate PO

— Suspected Lemierre syndrome

— Inability to tolerate oral fluids/antibiotics

— Toxic appearance, hemodynamic instability

— Need for IV antibiotics (deep neck infection, complicated case)

— Significant comorbidities (immunocompromise, congenital heart disease)

— Suspected ARF with carditis — admit for echo and management

— Failure of outpatient therapy with progression

— Streptococcal toxic shock syndrome: hypotension, multiorgan failure → IV fluids, vasopressors, IV penicillin + clindamycin (clindamycin suppresses toxin production), consider IVIG

— Airway compromise requiring intubation

— Severe sepsis/septic shock

— Lemierre with massive septic emboli or respiratory failure

— ENT: recurrent tonsillitis (Paradise criteria), peritonsillar abscess, sleep-disordered breathing, suspected deep neck infection

— Cardiology: confirmed or suspected rheumatic carditis

— Nephrology: PSGN with significant renal dysfunction or atypical course

— Infectious disease: recurrent invasive GAS, immunocompromised host

— Neurology: Sydenham chorea or PANDAS evaluation

CCS pearl: In a CCS scenario of streptococcal toxic shock, sequence within the first hour: IV access ×2, NS bolus 20 mL/kg, blood cultures, IV penicillin G + clindamycin, ICU admission, vasopressors if hypotensive after fluids, IVIG consideration, ENT/surgery consult if source identified.

Outpatient management suffices for most uncomplicated pediatric pharyngitis. Escalate when:

Emergency department or urgent ENT consult:

Hospital admission criteria:

ICU admission:

Subspecialty referrals:

Key Differentials — Other Infectious Pharyngitides

— Cause exudative pharyngitis indistinguishable from GAS clinically

— More common in adolescents/young adults

— Detected on culture (not RADT)

— Do not cause ARF; treatment debated but often given for symptom relief

— Subacute pharyngitis with cough, low-grade fever

— School-age and adolescents

— Treat with macrolide if pneumonia coexists; pharyngitis alone usually self-limited

— Adolescents/young adults with persistent severe sore throat

— Risk of Lemierre syndrome

— Treat with penicillin + metronidazole or ampicillin-sulbactam if suspected

— Adolescents/young adults; pharyngitis with scarlatiniform rash

— Treat with macrolide

— Sexually active adolescents; often asymptomatic or mild exudative pharyngitis

— NAAT pharyngeal swab

— Ceftriaxone 500 mg IM single dose; treat presumptively for chlamydia coexposure

— Unvaccinated children; thick grey pseudomembrane that bleeds when scraped; bull-neck; myocarditis, neuropathy

— Diphtheria antitoxin + erythromycin or penicillin; respiratory isolation; public health notification

— Mononucleosis-like syndrome with rash, oral ulcers, lymphadenopathy

— HIV RNA PCR (antibody may be negative)

Key distinction: A sexually active adolescent with mild persistent sore throat, negative GAS testing, and pharyngeal exudate warrants gonococcal/chlamydial NAAT of the pharynx — not repeated GAS testing or empiric amoxicillin.

Group C and G streptococci:

Mycoplasma pneumoniae and Chlamydophila pneumoniae:

Fusobacterium necrophorum:

Arcanobacterium haemolyticum:

Neisseria gonorrhoeae:

Corynebacterium diphtheriae:

Primary HIV infection:

Tularemia (oropharyngeal form): rare, exposure to rabbits/water; ulcers and exudates

Acute HSV pharyngitis: vesicles/ulcers, gingivostomatitis in young children

Key Differentials — Non-Infectious and Mimics

— Chronic or seasonal sore throat, sneezing, itchy eyes, clear rhinorrhea

— No fever, no exudate

— Treat with intranasal corticosteroids, oral antihistamines

— Morning sore throat, hoarseness, cough, sour taste

— No fever

— Lifestyle measures; PPI trial if persistent

— Smoke exposure (secondhand smoke, vaping), dry air, pollution

— History-driven diagnosis

— Sudden onset in toddler; persistent localized pain; drooling

— Direct visualization or imaging

— Penetrating oral trauma (falling with object in mouth); risk of carotid injury if posterior pharyngeal injury

— Imaging if concern

— Rare in children; neck pain radiating to throat, may mimic pharyngitis

— Children <5 years; fever ≥5 days + 4 of 5: bilateral nonexudative conjunctivitis, strawberry tongue/red cracked lips, polymorphous rash, extremity changes (palmar erythema/desquamation), cervical lymphadenopathy >1.5 cm

— Echocardiogram; IVIG + aspirin

— Often confused with scarlet fever — Kawasaki has conjunctivitis and extremity changes; scarlet fever has sandpaper rash and circumoral pallor

— Recurrent episodes every 3–6 weeks with high fever, exudative pharyngitis, cervical adenitis

— Negative GAS testing during episodes

— Single-dose prednisone aborts episodes; tonsillectomy curative in many

Board pearl: A 4-year-old with recurrent stereotyped episodes of high fever, exudative pharyngitis, and aphthous ulcers every 4 weeks with complete wellness between — think PFAPA, not recurrent strep. Single-dose prednisone is diagnostic and therapeutic.

Allergic rhinitis with post-nasal drip:

Gastroesophageal reflux (GERD/LPR):

Environmental irritants:

Foreign body:

Trauma:

Acute thyroiditis:

Kawasaki disease:

PFAPA syndrome (Periodic Fever, Aphthous stomatitis, Pharyngitis, Adenitis):

Behçet disease, cyclic neutropenia, autoimmune: recurrent oral ulcers

Malignancy: lymphoma, leukemia presenting with tonsillar mass or persistent lymphadenopathy

Discharge Planning and Secondary Prevention

— Complete 10 days of antibiotics even if symptoms resolve (5 days for azithromycin)

— Antipyretics/analgesics as needed

— Hydration plan

— Anticipatory guidance on signs of complication

— Worsening throat pain, neck swelling, drooling, trismus → return immediately

— Tea-colored urine, periorbital swelling 1–3 weeks later → return for PSGN evaluation

— New joint pain, chest pain, rash, jerky movements 2–4 weeks later → ARF evaluation

— Replace toothbrush after 24–48 hours of antibiotics to prevent reinfection within household

— Reasonable advice though limited evidence

— After 24 hours of antibiotics + afebrile for GAS

— Viral pharyngitis: return when afebrile and feeling well

— Identify and treat household carriers only if recurrent infections cluster in a family

— Consider tonsillectomy if meeting Paradise criteria

— Hand hygiene, avoid sharing utensils/drinks

— Benzathine penicillin G IM q4 weeks (preferred over oral due to adherence)

— Duration based on cardiac involvement (see chunk 9)

— Document each dose; coordinate with school/family

— No GAS vaccine currently available (in development)

— Ensure routine immunizations up to date (especially varicella — varicella-associated invasive GAS is a recognized complication)

— Annual influenza vaccine reduces viral pharyngitis that triggers superinfection

— Distinguish viral from bacterial for parents — explain antibiotic stewardship to reduce future expectations

Step 3 management: When discharging a child treated for GAS, schedule a follow-up only if symptoms persist >72 hours, complications develop, or for ARF/PSGN concern weeks later — no routine "test of cure" is recommended in asymptomatic children.

Discharge medication checklist for uncomplicated GAS pharyngitis:

Counseling on return precautions:

Toothbrush and contact items:

School return:

Recurrent GAS pharyngitis prevention:

Secondary ARF prophylaxis (post-rheumatic fever):

Vaccinations:

Anticipatory guidance:

Follow-Up, Monitoring, and Family Counseling

— None required if symptoms resolve

— Reassess at 48–72 hours if symptoms persist or worsen

— Test of cure not recommended unless:

▪ History of rheumatic fever

▪ Symptoms recur shortly after treatment completion

▪ Outbreak setting

— Symptom improvement expected within 24–48 hours of antibiotics

— Persistent fever beyond 48–72 hours → reassess for complications (abscess, alternative diagnosis, EBV, treatment failure)

— Watch for rash (allergic reaction vs EBV)

— C. difficile concerns if diarrhea develops, especially with clindamycin

— Cardiology follow-up with serial echocardiograms

— Adherence to monthly benzathine penicillin documented

— Annual reassessment of valve status

— Dental hygiene education (endocarditis prevention)

— BP and UA at 1, 3, 6 weeks

— C3 normalizes by 6–8 weeks (if persistently low → reconsider C3 glomerulopathy)

— Most children recover fully; long-term renal follow-up if proteinuria/hypertension persists

— Provide families with episode log: date, fever, exam findings, GAS test result

— Refer to ENT once Paradise criteria approached

— Antibiotic stewardship: viruses cause most sore throats; antibiotics don't help viral illness and have real risks

— Importance of completing full antibiotic course

— Hygiene: handwashing, covering coughs, no sharing of utensils

— When to seek emergency care vs primary care

— Notify if cluster of cases

— Public health reporting not required for GAS (unless invasive disease — varies by state)

CCS pearl: Schedule a 48–72 hour reassessment in CCS for any child treated empirically or with severe presentation; advance the clock and recheck — failure to improve should prompt reconsideration of the diagnosis, evaluation for abscess, or EBV testing.

Routine follow-up for uncomplicated GAS pharyngitis:

Monitoring during treatment:

Post-ARF monitoring:

Post-PSGN monitoring:

Recurrent tonsillitis tracking:

Family education:

School and daycare communication:

Ethical, Legal, and Patient Safety Considerations

— Inappropriate antibiotic prescribing for viral pharyngitis is a major patient safety and public health concern

— Counsel parents that antibiotics for viral illness cause harm (allergic reactions, C. difficile, resistance) without benefit

— Use shared decision-making; resist pressure to "just in case" prescribe

— Document rationale for withholding antibiotics

— Peritonsillar abscess drainage, tonsillectomy require parental consent; assent from older children (typically ≥7 years) is ethically appropriate

— Discuss risks: bleeding, infection, anesthesia

— Record Centor/McIsaac score, test results, and rationale for treatment

— Avoid empiric antibiotics without testing in low-probability cases — a known stewardship metric

— When transferring a child with deep neck infection to a tertiary center, communicate antibiotics given (drug, dose, time), airway status, imaging findings

— Handoff failures in pediatric airway emergencies are high-risk

— Diphtheria: reportable to public health in all states

— Invasive GAS (bacteremia, necrotizing fasciitis, STSS): reportable in most jurisdictions

— Sexually transmitted gonococcal pharyngitis in minors: assess for abuse and report per state mandatory reporting laws

— STI testing (gonorrhea, HIV) for sexually active adolescents — most states allow confidential treatment without parental consent

— Document discussions about confidentiality and its limits (safety concerns, mandatory reporting)

— Many "penicillin allergies" are mislabeled — clarify the actual reaction; document type and severity to guide future treatment

— A child labeled "penicillin allergic" because of an EBV rash should have the label removed to ensure access to first-line antibiotics lifelong

— Access to outpatient follow-up affects ARF prevention; ensure prescription affordability

Board pearl: A 14-year-old presenting alone with gonococcal pharyngitis — treat confidentially per state minor consent laws for STI care, screen for sexual abuse, and report if abuse is suspected; parental notification is not required for the STI itself in most states.

Antibiotic stewardship:

Informed consent for procedures:

Test-and-treat documentation:

Transitions of care:

Mandatory reporting:

Confidentiality in adolescents:

Medication errors and allergy clarification:

Equity considerations:

High-Yield Associations and Rapid-Fire Facts

Key distinction: GAS pharyngitis causes both ARF (preventable) and PSGN (not preventable) — antibiotics interrupt the autoimmune cascade for ARF but not for the immune-complex glomerulonephritis of PSGN.

GAS = Streptococcus pyogenes = group A beta-hemolytic strep; bacitracin-sensitive, PYR-positive

No documented penicillin resistance in GAS — penicillin remains first-line worldwide

Centor criteria (McIsaac modification): Fever, no Cough, tender Anterior cervical nodes, Tonsillar exudate, age (3–14: +1; ≥45: −1)

Treat within 9 days of symptom onset to prevent ARF

Antibiotics prevent ARF, not PSGN

24-hour rule: noninfectious after 24h of antibiotics; return to school

Scarlet fever = GAS + erythrogenic exotoxin → sandpaper rash, strawberry tongue, Pastia lines, circumoral pallor

Amoxicillin rash + sore throat + posterior lymphadenopathy + splenomegaly = EBV, not penicillin allergy

EBV: heterophile (Monospot) may be falsely negative <4 years — use VCA IgM/IgG, EBNA

Avoid contact sports for 3–4 weeks in EBV (splenic rupture)

Mononucleosis triad: fever, pharyngitis, lymphadenopathy ± hepatosplenomegaly

Atypical lymphocytes >10% with pharyngitis → EBV

Coxsackie A → herpangina (posterior oropharynx vesicles); hand-foot-mouth adds extremity lesions

HSV gingivostomatitis: anterior mouth, gingiva, drooling, fever in toddlers; treat with acyclovir if <72–96 h

Adenovirus: pharyngoconjunctival fever; outbreaks in pools/camps

PFAPA: every 3–6 weeks, single-dose prednisone aborts

Kawasaki vs scarlet fever: Kawasaki has conjunctivitis + extremity changes; scarlet fever has sandpaper rash + circumoral pallor

Lemierre syndrome: adolescent, Fusobacterium, IJ vein thrombus, septic pulmonary emboli

STSS treatment: penicillin + clindamycin (clindamycin halts toxin production), IVIG considered

Diphtheria: grey pseudomembrane, bull-neck; antitoxin + erythromycin; reportable

Paradise criteria: 7/5/3 episodes over 1/2/3 years for tonsillectomy

PSGN: 1–3 weeks post-pharyngitis, hematuria, RBC casts, low C3, normal C4, ASO/anti-DNase B

ARF: 2–4 weeks post-pharyngitis, Jones criteria, mitral valve most affected

Sydenham chorea: late ARF manifestation, can occur up to 6 months later

Board Question Stem Patterns

— 8-year-old, sudden sore throat, fever 39°C, no cough, tender anterior nodes, tonsillar exudate, palatal petechiae

— RADT positive

— Answer: amoxicillin 50 mg/kg/day × 10 days (or penicillin V); not azithromycin (unless allergic), not test of cure

— 6-year-old, sore throat with prominent cough, rhinorrhea, hoarseness

— Answer: no testing, no antibiotics, supportive care

— 16-year-old, sore throat 1 week, exudative tonsils, posterior cervical adenopathy, splenomegaly, developed maculopapular rash after starting amoxicillin

— Answer: heterophile antibody test (or EBV serology); avoid contact sports 3–4 weeks; rash is not true penicillin allergy

— 9-year-old, untreated sore throat 3 weeks ago, now migratory polyarthritis, new murmur, fever, elevated ESR

— Answer: ASO/anti-DNase B titers, echocardiogram; initiate penicillin + anti-inflammatory; start secondary prophylaxis

— 7-year-old, sore throat 2 weeks ago, now tea-colored urine, periorbital edema, BP 140/90

— Answer: UA (RBC casts), low C3, ASO; supportive care (salt restriction, loop diuretic, BP control); antibiotics do not change PSGN course

— 10-year-old with culture-positive GAS, history of anaphylaxis to amoxicillin

— Answer: clindamycin or azithromycin (not cephalexin if true anaphylaxis)

— 13-year-old, sore throat 4 days, now trismus, muffled voice, uvular deviation

— Answer: needle aspiration/I&D, IV ampicillin-sulbactam, ENT consult

— 4-year-old, recurrent stereotyped episodes every 4 weeks with fever, exudative pharyngitis, aphthous ulcers, well between

— Answer: single-dose prednisone

— 2-year-old with low-grade fever, exudative pharyngitis, conjunctivitis

— Answer: viral (adenovirus); no testing for GAS, supportive care

Board pearl: When a stem includes "cough, rhinorrhea, hoarseness, or conjunctivitis" alongside sore throat, the correct answer almost always excludes GAS testing and antibiotics. Recognize these "viral-defining" symptoms as protective against the wrong-answer trap of empiric antibiotics.

Stem 1 — Classic GAS:

Stem 2 — Centor 1:

Stem 3 — EBV trap:

Stem 4 — ARF:

Stem 5 — PSGN:

Stem 6 — Penicillin allergy:

Stem 7 — Peritonsillar abscess:

Stem 8 — PFAPA:

Stem 9 — Toddler:

One-Line Recap

Pediatric pharyngitis is mostly viral, but school-age children with Centor ≥2 features (fever, no cough, tender anterior cervical nodes, tonsillar exudate) should be tested with RADT plus back-up culture if negative, and confirmed GAS treated with amoxicillin 50 mg/kg/day × 10 days to prevent rheumatic fever — not PSGN.

Board pearl: The two most-tested traps in pediatric pharyngitis are (1) prescribing antibiotics for viral pharyngitis (cough/coryza/conjunctivitis) and (2) believing antibiotics prevent PSGN — both are wrong. Master Centor scoring, the 10-day amoxicillin regimen, EBV recognition, and the ARF-yes-PSGN-no rule, and the vast majority of Step 3 pharyngitis questions become straightforward pattern recognition rather than calculation.

Diagnose by selection, not reflex: avoid testing in clearly viral presentations or children <3 years; use Centor/McIsaac to risk-stratify ages 3–15

First-line antibiotic = amoxicillin or penicillin V × 10 days; cephalexin for non-severe penicillin allergy, clindamycin or azithromycin for anaphylaxis; benzathine penicillin G IM for adherence concerns

Antibiotics prevent ARF (within 9 days) but not PSGN; return to school after 24 hours of treatment and afebrile; no routine test of cure

Recognize mimics: EBV (amoxicillin rash, posterior adenopathy, splenomegaly), PFAPA (periodic stereotyped episodes), Kawasaki (conjunctivitis + extremity changes), peritonsillar abscess (trismus + muffled voice), gonococcal pharyngitis in adolescents, and Lemierre syndrome (persistent severe pharyngitis with neck pain and pulmonary emboli)