Signs of Infection for a Posterior Pharyngeal Lesion

Confirmatory Signs of Infection

Purulent drainage from or around the lesion is a confirmatory sign of active infection 2
Muffled voice strongly suggests deep space infection such as peritonsillar or parapharyngeal abscess 1
Drooling indicates severe pain with swallowing or airway compromise from infection 1
Tonsillar asymmetry with one tonsil pushed medially suggests peritonsillar abscess 3

Fever is common with bacterial infections, though its absence does not rule out serious infection like peritonsillar abscess 1
Severe odynophagia that limits oral intake 1
Tonsillopharyngeal exudates suggest bacterial infection, particularly Group A Streptococcus 4, 5
Tender anterior cervical lymphadenopathy indicates regional lymph node response to infection 4, 5
Erythema and swelling of the posterior pharynx or tonsils 4
Soft palate petechiae suggest streptococcal infection 4

Difficulty swallowing with drooling suggests impending airway obstruction 6, 1
Neck tenderness or swelling may indicate deep space infection or Lemierre syndrome 6, 3
New-onset snoring with bilateral tonsillar enlargement indicates acute upper airway obstruction 1
Severe pharyngitis in adolescents/young adults should raise suspicion for Fusobacterium necrophorum infection and Lemierre syndrome 6, 1
Trismus suggests peritonsillar abscess 1

The American Academy of Otolaryngology-Head and Neck Surgery suggests that the absence of fever does not rule out peritonsillar abscess and severe airway obstruction 1
A nontender neck mass is actually more suspicious for malignancy than a tender one, so tenderness with a posterior pharyngeal lesion suggests infection rather than cancer 3

Viral infections typically present with cough, rhinorrhea, hoarseness, or conjunctivitis 6, 5, 7
Oral ulcers or vesicles are also characteristic of viral infections 5
Diarrhea can be a symptom of viral infection 4
Bacterial infections, particularly Group A Streptococcus, typically present with sudden-onset severe sore throat without cough 4, 7
Tonsillar exudates are also characteristic of bacterial infections 4, 5
Scarlatiniform rash and palatal petechiae can be symptoms of bacterial infection 4

The American College of Radiology recommends a CT scan with contrast if peritonsillar or parapharyngeal abscess is suspected based on muffled voice, drooling, severe odynophagia, or tonsillar asymmetry 1