*Infections are the cause of an acute sore throat in the overwhelming majority of cases.
Red flag / life-threatening ddx.
-s/sx of epiglottitis: Acute onset of dysphagia, odynophagia, drooling, high fever, anxiety, and muffled voice;
-s/sx of peritonsillar abscess: fever, sore throat, dysphagia, trismus, a muffled voice (“hot potato” voice), malaise, Odynophagia / severe unilateral pain, Otalgia (ipsilateral), severe sore throat, worse on one side, drooling, cervical lymphadenitis, red, swollen soft palate with uvula deviation to contralateral side and enlarged tonsil; foul-smelling breath (fetor); sometimes large tonsillar swelling.
-s/sx of retropharyngeal abscess: inability to swallow, worsening of sx after several days, bulging of the retropharyngeal wall.
-s/sx of diphtheria: pseudomembrane, cervical lymphadenopathy,
-s/sx of submandibular space infections (Ludwig’s angina)
-s/sx of a retromolar abscess and neoplasm (lymphoma or carcinoma)
Noninfectious causes of a sore throat
-Dry air,
-Persistent cough;
-Postnasal drip;
-Gastroesophageal reflux disease (GERD);
-Acute thyroiditis;
-Neoplasm;
-Allergies; Smoking
-Thrush
-Smoking
Viral pharyngitis (the most common cause of a sore throat)
-Rhinovirus, Adenovirus, Coronavirus,
-Influenza A&B virus; Parainfluenza;
-EBV;
-Cytomegalovirus (CMV);
-HIV;
-HSV1/HSV2, HHV-6
Infectious mononucleosis (usually caused by EBV)
Bacterial infection
–Group A beta-hemolytic streptococcus (GABHS)
-Group C beta-hemolytic streptococci;
-Neisseria gonorrhoeae
-Corynebacterium diphtheriae;
-Mycoplasma pneumoniae;
-Chlamydophila pneumoniae; Fusobacterium necrophorum
Gonococcal pharyngitis (in sexually active patients)
Uvulitis
Peritonsillar abscess
Retropharyngeal abscess /Retropharyngeal space infection infection
Diphtheria
Epiglottitis
Angioedema
Herpes simplex
Primary HIV
Acute thyroiditis
Submandibular space infection
Arcanobacterium haemolyticum
Tularemia
Lemierre syndrome (Postanginal septicemia)
Kawasaki disease
Measles
Behcet syndrome
Hand-foot-and-mouth disease
Oropharyngeal cancer
Aphthous ulcers
Repeated strangulation in domestic abuse
Further Reading
Am Fam Physician. 2004 Mar 15;69(6):1465-1470. https://www.aafp.org/afp/2004/0315/p1465.html
Nurse Pract. 1996 Apr;21(4):38-42, 44, 47-8. https://www.ncbi.nlm.nih.gov/pubmed/8801491
https://online.epocrates.com/diseases/535/Acute-pharyngitis/Differential-Diagnosis
Symptom to Diagnosis: An Evidence-Based Guide, 3e (Access Medicine)