3.12 Pharyngitis (Sore Throat)
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agk's Library of Common Simple Emergencies

Presentation
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The patient with a bacterial pharyngitis 
complains of a rapid onset of throat pain 
worsened by swallowing. There is usually a 
fever, pharyngeal erythema, and a purulent, 
patchy, yellow, gray or white exudate, tender 
cervical adenopathy, headache and absence of 
cough. Viral infections are typically accomp- 
anied by conjunctivitis, nasal congestion, 
hoarseness, cough, aphthous ulcers on the soft 
palate and myalgias. It is helpful to differ- 
entiate pain on swallowing (odynophagia) from 
difficulty swallowing (dysphagia), the latter 
being more likely caused by obstruction or 
abnormal muscular movement.

What to do:
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- First examine the ears, nose, and mouth, 
   which are, after all, connected to the 
   pharynx, and often contain clues to the 
   diagnosis.
- Depress the tongue with a blade, have the 
   patient raise his soft palate by saying 
   "ah," inspect the posterior pharynx, and 
   swab both tonsillar pillars for a culture. 
   (You can decide later whether you really 
   need to plant the culture. Rapid strep tests 
   may provide results in a few minutes, while 
   cultures may take 1-2 days to incubate and 
   interpret. This delay does not alter the 
   effectiveness of therapy, however. Treatment 
   may begin up to nine days after symptoms and 
   still prevent rheumatic fever.)
- If you are in the middle of an epidemic of 
   group A streptococcal pharyngitis; if the 
   patient is between 3 and 25 years old, has a 
   history of rheumatic fever and recurrent 
   "strep throats" and has been exposed; and if 
   the patient has a red throat, fever, tender 
   anterior cervical nodes, and no viral URI 
   symptoms (or any convincing subset of the 
   above); give antibiotics. Throat culture is 
   optional, at the preference of the follow-up 
   physician. The recommended treatment for 
   streptococcal pharyngitis is oral penicillin 
   VK 250mg q8h for 10 days. Injectable 
   penicillins are preferred for patients 
   unlikely to finish ten days of pills and 
   those with a personal or family history of 
   rheumatic fever. Patients under 60 lbs (30 
   kg) get one intramuscular injection of 
   benzathine penicillin G 600,000 units and 
   those over 60 lbs get 1,200,000u im. For 
   those allergic to penicillin give 
   erythromycin 250mg qid (or 333mg of 
   erythromycin base tid) for 10 days. 
   Amoxicillin offers no significant advantage 
   for treating group A strep.
- When the infection is not clearly bacterial 
   or you are unsure about the need for an 
   antibiotic (or you or the patient "need to 
   know" if this is a strep infection) then you 
   may obtain a rapid strep test. If the rapid 
   strep test is positive, then treat with 
   antibiotics as above. If the test is 
   negative or unavailable and you have a high 
   clinical suspicion that this is a viral 
   pharyngitis, provide symptomatic treatment 
   (below), send a culture, and hold 
   antibiotics pending results.
- For reistant or recurrent infections with 
   possible beta-lactamase-producing co- 
   pathogens, consider instead 10 days of 
   cephalexin (Keflex), cefadroxil (Duricef, 
   Ultracef), cefaclor (Ceclor), or cefurooxime 
   (Ceftin, Zinacef).
- If you suspect [mononucleosis], draw blood 
   for atypical lymphocytes and a heterophile 
   or monospot to confirm the diagnosis.
- Relieve pain with acetaminophen ibuprofen, 
   aspirin, warm saline gargles, and gargles or 
   lozenges containing phenol as a mucosal 
   anesthetic (e.g., Chloraseptic, Cepastat). A 
   one-to-one mixture of diphenhydramine and 
   kaolin-pectin suspension can also provide 
   temporary relief of throat pain. Viscous 
   Xylocaine gargles anesthetize the throat but 
   patients may still have difficult swallowing 
   because of the lack of sensation. For severe 
   pain in patients without contraindications, 
   dexamethasone 10mg im once has been used 
   along with antibiotics.

What not to do:
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- Do not miss an acute epiglottitis or supra- 
   glottitis. In a child, this presents as a 
   sudden, severe pharyngitis, with a gutteral, 
   rather than hoarse voice (because it hurts 
   to speak), drooling (because it hurts to 
   swallow), and respiratory distress (because 
   swelling narrows the airway). Adults usually 
   have a more gradual onset, over several 
   days, and are not as prone to a sudden 
   airway occlusion, unless they present later 
   in the progression of the swelling, already 
   with some respiratory distress.
- Do not give ampicillin to a patient with 
   mononucleosis. The resulting rash helps make 
   the diagnosis, and does not imply ampicillin 
   allergy, but can be uncomfortable.
- Do not miss abscesses, which usually require 
   hospitalization and intravenous penicillin, 
   if not drainage. Peritonsillar abcesses or 
   cellulitis make the tonsillar pillar bulge 
   towards the midline. Retropharyngeal 
   abscesses (and epiglottitis) may require 
   soft tissue lateral neck films to visualize.
- Do not miss gonococcal pharyngitis, which can 
   produce a mild clinical syndrome and 
   requires special cultures on Thayer-Martin 
   medium.
- Do not miss the rare but deadly causes of 
   sore throat. A patient with paresthesia at 
   the site of an old, healed bite and painful 
   spasms when he even thinks of swallowing may 
   have rabies. A patient with facial palsy, 
   myocarditis, and a tough, white, membrane 
   adherent to the posterior pharynx may have 
   diptheria. You cannot diagnose them unless 
   you think of them.

Discussion
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The general public knows to see a doctor for a 
sore throat, but the actual benefit of this 
visit is unclear. Rheumatic fever is a sequela 
of about 1% of group A streptococcal infect- 
ions, and only about 10% of sore throats seen 
by physicians represent group A streptococcal 
infections. Post-streptococcal glomerulo- 
nephritis is usually a self-limiting illness 
and is not prevented with antibiotic treatment. 
Penicillin therapy does avoid acute rheumatic 
fever and may sometimes reduce symptoms or 
shorten the course of a sore throat. Anti- 
biotics probably inhibit progress of the 
infection into tonsillitis, peritonsillar and 
retropharyngeal abscesses, adenitis, and 
pneumonia.

Group A streptococcal infection cannot be 
diagnosed reliably by clinical signs and 
symptoms. Typically, a quarter of throat 
cultures grown group A strep, and half of those 
represent carriers who do do not raise anti- 
streptococcal antibodies and risk rheumatic 
fever. Rapid strep screens are less sensitive 
than cultures. The best approach to the 
identification and treatment of streptococcal 
pharyngitis depends on the prevalence of group 
A streptococcal infection in the patient 
population, the cost and availability of 
culture and rapid test methods, the reliability 
of communication and follow up and the relative 
values of cost, antibiotic overuse, and adverse 
outcomes.

References:
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- Coonan KM, Kaplan EL: In vitro susceptibility 
   of recent North American group A 
   streptococcal isolates to eleven oral 
   antibiotics. *Pediatr Infect Dis J* 1994; 
   13:630-635.
- Hall CB, Breese BB: Does Penicillin make 
   Johnny's strep throat better? *Pediatric 
   Infectious Disease* 1984:3:7-9.
- O'Brien JF, Meade JL, Falk JL: Dexamethasone 
   as adjuvant therapy for severe acute 
   pharyngitis. *Ann Emerg Med* 1993; 
   22:212-214.
- Huovinen P, Lahhtonen R, Ziegler T et al: 
   Pharyngitis in adults: the presence and 
   coexistence of viruses and bacterial 
   organisms. *Ann Intern Med* 1989; 
   110:612-616.

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