Primary pathogens (Staphylococcus aureus (MSSA) · Group A Streptococcus (Streptococcus pyogenes) · Streptococcus anginosus group (especially with odontogenic/oropharyngeal source))
Clinical context (Acute unilateral tender enlarged cervical node(s) with fever and overlying erythema; most cases are bacterial, but consider viral/reactive nodes when diffuse bilateral nodes with URI symptoms and no focal tenderness (AAP, CPS))
First-line therapy
Cephalexin • p.o. • 25–25 mg/kg/dose • 3×/day
Max 1000 mg/dose · Max 3000 mg/day · Duration: 7–10 days · Reassess at 48–72 h; if no improvement, evaluate for abscess, atypical infection, or alternate diagnosis; extend duration if complicated
• Standard empiric choice when uncomplicated bacterial lymphadenitis is suspected without MRSA risk factors and without odontogenic/oropharyngeal anaerobic concern (AAP, CPS, IDSA SSTI principles).
• Prefer broader coverage (e.g., amoxicillin/clavulanate) when dental source, gingivitis/periodontal disease, foul breath, or suspected Streptococcus anginosus/anaerobes (CPS, AAP).
• Consider MRSA-active therapy (clindamycin where susceptible) when purulence, prior MRSA, household MRSA, failed beta-lactam at 48–72 h, or high local MRSA prevalence (IDSA SSTI, CPS).
• Urgent ED/hospital assessment if toxic appearance, dehydration, airway symptoms, or deep neck space warning signs (trismus, drooling, muffled voice, torticollis, stridor) (CPS, NICE principles).
• If fluctuant mass or abscess suspected, antibiotics alone may be insufficient — consider ultrasound and aspiration/drainage (AAP, CPS, IDSA abscess principles).
Dose is calculated using the amoxicillin component.
Max 875 mg/dose (amoxicillin) · Max 1750 mg/day · Duration: 7–10 days · Use when dental source or mixed oral flora suspected; provides MSSA/streptococci plus oral anaerobe coverage (AAP, CPS, IDSA SSTI oral options)
• Likely viral/reactive lymphadenopathy: bilateral non-tender nodes with URI symptoms, generalized adenopathy, or no focal erythema — antibiotics usually not indicated; observe and follow-up (AAP, CPS).
• Ultrasound: consider when fluctuance is uncertain on exam, mass is large/persistent, no improvement after 48–72 h of antibiotics, or to evaluate for drainable abscess (AAP, CPS).
• Aspiration/surgical drainage: indicated for suppurative lymphadenitis with abscess, fluctuance, or failure to improve; obtain culture when draining to target therapy (IDSA abscess principles, AAP).
• MRSA coverage: add/switch when purulent drainage, prior MRSA, household MRSA, penetrating trauma, or beta-lactam failure at 48–72 h; clindamycin where susceptible (IDSA SSTI, CPS).
• Viral vs bacterial: bacterial usually unilateral, tender, erythematous, febrile; viral/reactive often bilateral, mobile, less tender with concurrent URI symptoms — avoid antibiotics when bacterial infection unlikely (AAP, CPS).
• Ultrasound indications: uncertain fluctuance, large node/mass, persistent symptoms, or no improvement in 48–72 h — helps identify abscess and guides aspiration (AAP, CPS).
• Drainage: aspiration or surgical drainage for suppurative/fluctuant nodes or abscess; send culture when draining to tailor antibiotics (IDSA abscess principles).
• Deep neck space warning signs: trismus, muffled voice, drooling, torticollis, stridor, respiratory distress, inability to handle secretions — urgent ED evaluation and imaging/ENT consult (CPS, NICE principles).
• IV→PO switch: when clinically improving, afebrile ≥24 h, tolerating oral intake, and no airway/complication concern — complete total 7–10 days effective therapy (CPS, IDSA principles).
• AAP Red Book — Cervical lymphadenitis (bacterial and atypical) (2024)
• IDSA — Practice guidelines for skin and soft tissue infections (principles for cellulitis/abscess and MRSA coverage) (2014)
