3.12 Pharyngitis (Sore Throat)
=======================================
agk's Library of Common Simple Emergencies
Presentation
------------
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:
-----------
- 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:
---------------
- 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
----------
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:
-----------
- 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.
----------------------------------------------------
from Buttaravoli & Stair: COMMON SIMPLE EMERGENCIES
Longwood Information LLC 4822 Quebec St NW Wash DC
1.202.237.0971 fax 1.202.244.8393
[email protected]
----------------------------------------------------
