A 32-year-old woman presents with a 3-day history of sore throat, fever (38.5°C), and mild dysphagia. On examination, both tonsils are enlarged, erythematous, and covered with white exudate. The anterior cervical lymph nodes are tender and enlarged. Throat culture is pending. The patient is started on oral penicillin V 500 mg QID. After 48 hours, her symptoms persist and fever remains at 38.8°C. She denies difficulty swallowing saliva or trismus. What is the most appropriate next step?

Explanation

## Management of Acute Tonsillitis: Treatment Failure and Abscess Exclusion ### Clinical Context: Failure to Respond to Initial Therapy **Key Point:** Acute tonsillitis typically responds to first-line antibiotics (penicillin or amoxicillin) within 48–72 hours. Persistent symptoms and fever after 48 hours of appropriate therapy warrant investigation for complications, particularly peritonsillar abscess. ### Why This Patient Requires Reassessment | Finding | Significance | |---------|-------------| | **Persistent fever after 48 hrs** | Suggests inadequate source control or complication | | **Continued dysphagia** | May indicate abscess formation | | **No trismus or severe dysphagia** | Argues against established abscess, but does not exclude early/forming abscess | | **Absence of uvula deviation** | Reassuring, but imaging still warranted given treatment failure | **High-Yield:** Treatment failure in acute tonsillitis is defined as persistence of fever and constitutional symptoms beyond 48–72 hours of appropriate antibiotics. The differential includes: - Peritonsillar abscess (most common complication) - Retropharyngeal abscess - Epiglottitis - Viral tonsillitis (no response to antibiotics) - Beta-lactamase-producing organism (resistant to penicillin V) ### Rationale for Switching to Amoxicillin-Clavulanate **Clinical Pearl:** Amoxicillin-clavulanate covers beta-lactamase-producing organisms (e.g., *Staphylococcus aureus*, anaerobes) that may be resistant to penicillin V alone. This is particularly relevant in treatment-failure scenarios. ### Role of Imaging ```mermaid flowchart TD A[Acute Tonsillitis on Antibiotics]:::outcome --> B{Response at 48-72 hrs?}:::decision B -->|Yes| C[Continue antibiotics, complete course]:::action B -->|No| D[Treatment failure]:::urgent D --> E{Clinical signs of abscess?}:::decision E -->|Clear signs: trismus, uvula deviation, bulge| F[Drainage + IV antibiotics]:::action E -->|Equivocal signs| G[Imaging: CT or Ultrasound]:::action G --> H{Abscess present?}:::decision H -->|Yes| F H -->|No| I[Switch to broad-spectrum antibiotic]:::action I --> J[Repeat assessment in 24-48 hrs]:::action ``` **Key Point:** In the absence of clear clinical signs of abscess (no trismus, no uvula deviation, no soft palate bulge), imaging is the safest next step to exclude a forming abscess before it becomes a surgical emergency. ### Why Amoxicillin-Clavulanate Is Preferred Over IV Ceftriaxone - **Oral amoxicillin-clavulanate** is appropriate for treatment failure without signs of severe systemic toxicity or airway compromise. - **IV ceftriaxone** is reserved for severe cases, immunocompromised patients, or those unable to tolerate oral intake. - This patient is maintaining oral intake (mild dysphagia, not severe) and is hemodynamically stable. **Mnemonic:** **ABCDE of Tonsillitis Management** - **A**ntibiotics (penicillin or amoxicillin first-line) - **B**road-spectrum (amoxicillin-clavulanate) if treatment failure - **C**omplications (abscess, retropharyngeal) — rule out with imaging - **D**rainage (needle aspiration or incision) if abscess confirmed - **E**valuation (repeat assessment after intervention) [cite:Dhingra 7e Ch 9; Harrison 21e Ch 309]