Acute Pharyngitis

 Acute Pharyngitis

 PATIENT HISTORY

The patient was a 6 year-old male who had been in good health with no significant medical problems. In late September he presented to his pediatrician’s office with a complaint of sore throat, fever, headache, and swollen glands in his neck for the past 36 h. On physical examination

(PE), he had a fever of 38◦C (100.4◦F), a red posterior pharynx, yellowish exudate on his tonsils, and multiple, enlarged, tender cervical lymph nodes.

 There were no other pertinent symptoms.

LABORATORY TESTS

  pain on swallowing, as well as erythema with or without exudate on the

tonsils and tender cervical lymph nodes. There are no clinical indicators

that would make it possible to accurately predict the cause of this child’s

pharyngitis. Laboratory tests are required to make a diagnosis.

When deciding whether to perform a laboratory test, clinical and epidemiological

features as well as the availability and usefulness of treatment

must be considered. While viruses are the most common cause

of acute pharyngitis in both adults and children, lab testing for viruses

is not warranted because antiviral agents are not used to treat acute

pharyngitis. Given the age of this patient, the absence of travel, and the

lack of suspicion of child abuse, GAS is the most likely etiologic agent.

Since GAS pharyngitis is the most commonly occurring form of pharyngitis

for which antibiotic therapy is indicated, lab testing should be directed

at ruling out GAS. Appropriate laboratory tests for this would

include:

Rapid strep test. This is not a culture; the test detects a unique carbohydrate

on the cell wall of GAS.

Throat culture. This test will grow the GAS organism from a throat

specimen taken from the patient and will require overnight incubation

at the minimum. Most labs offer a specific “rule out GAS”

throat culture.

The specimen required for each of these tests is a throat swab. Use of a

double-swab format allows one to obtain sufficient specimen to perform

both tests if necessary. As with any microbiology test, the quality of the

results is contigent on whether the laboratory receives a well-taken specimen.

The double swab should be firmly rubbed over much of the surface

of both tonsils and the posterior pharyngeal area and rolled to ensure

that there is ample specimen is on each swab tip. If exudate is present, it

should also be sampled on the same swabs. Care should be taken to avoid

touching other areas of the oropharynx, mouth, and tongue.

DirectGramstains fromthroat swabs are not at all useful becausemany

bacteria normally reside in the throat, including nonpathogenic streptococci

that have Gram stain appearance identical to that of GAS.

 TREATMENT AND PREVENTION

Treatment of group A streptococcal pharyngitis is important in order to

relieve the patient’s symptoms and to prevent the transmission to others.

Prompt treatment will also prevent complications such as peritonsillar abscess

and acute rheumatic fever. Symptoms will often disappear within

3–4 days even without antibiotics, but early antibiotics can shorten the

duration of symptoms. Pharyngitis caused by S. pyogenes can be effectively

treated with a penicillin. In children, like this patient, amoxicillin

is routinely prescribed. Patients must complete the course of antibiotic to

eradicate the organisms from the pharynx. For patients who are allergic

to penicillin, erythromycin would be an acceptable alternative. If left untreated,

patients with GAS infection may develop the sequellae of heart

valve damage (RF) or kidney damage (GN).

Susceptibility tests on GAS would not be performed since resistance

to penicillin has not been documented in these organisms to date. Carriers

maintain S. pyogenes in their throats despite appropriate antibiotic therapy;

it is not because the organisms are resistant to penicillin. Carriers are not

symptomatic but can spread the organism to others who may develop an

infection.