Pharyngitis is one of the most common reasons for an office visit. The authors review the key diagnostic considerations and management strategies for this condition and the complication of peritonsillar abscess.

Acute pharyngitis accounts for 1.1% of visits in the primary care setting and is ranked in the top 20 reported primary diagnoses resulting in office visits. Peritonsillar abscess (PTA), a potentially serious complication of pharyngitis, is also very common. There are estimated to be 45,000 cases annually, totaling approximately $150 million in health care costs. In this article, we review the accurate and rapid diagnosis and treatment of both pharyngitis and PTA. We will also discuss the proper technique for needle aspiration and drainage of a PTA.


Clinical Presentations

Pharyngitis is most often caused by a viral pathogen, but approximately 5% to 15% of cases are caused by group A beta-hemolytic streptococcus (GABHS). Distinguishing between bacterial and viral causes of pharyngitis is challenging. Rhinorrhea, cough, hoarseness, and conjunctivitis with a complaint of sore throat usually indicates a viral origin. Bacterial pharyngitis may be associated with high fever, chills, a very painful and swollen throat, and marked erythema and exudate.

Clinical findings alone, however, do not adequately distinguish viral from bacterial pharyngitis. Viral infections often present with exudates and erythema, and bacterial infections can appear subacute. While it is important to diagnose Streptococcus as a cause of pharyngitis, most viral pathogens do not need to be accurately identified. Important viral pathogens that deserve individual testing include influenza, mononucleosis, and HIV.

Patients with PTA will report fever, malaise, and a sore and swollen throat more often than patients with pharyngitis. A “hot potato” voice may be heard during conversation with the patient. Odynophagia, dysphagia, otalgia, and trismus can also provide clues to the diagnosis. With significant infection, the patient may complain of drooling and an inability to eat or drink and exhibit signs of severe dehydration.


PHYSICAL EXAM FINDINGS

The temperature of the patient is likely to be elevated, but the absence of fever does not exclude the diagnosis of either pharyngitis or PTA. The severity of the fever also does not reliably distinguish between viral and bacterial pharyngitis. Tachypnea, stridor, and respiratory distress may be present if a PTA has grown large enough to impair respirations; these findings should prompt the physician to immediately call for airway assistance. Inspection of the oropharynx in a patient complaining of sore throat is required for diagnosis of PTA.

The physical exam may find a range of presentations, from a nontoxic patient in minimal distress to a toxic-appearing patient who is drooling and in significant distress. Palpation of the neck and face may reveal tender cervical lymphadenopathy. The intraoral exam may uncover anything from a normal-appearing pharynx to a laterally and inferiorly deviated uvula, indicating PTA. Areas of erythema and tonsillar size and swelling should be noted on examination. In PTA, an area of prominence may be noted over the tonsil, and the tonsil itself will appear erythematous and edematous and may also be covered with a white exudate. If visual examination is not sufficient to differentiate PTA from cellulitis or pharyngitis, digital palpation of the affected area may assist in revealing a fluctuant mass.


DIAGNOSING AND TREATING PHARYNGITIS

As noted earlier, most cases of pharyngitis are viral. However, the sequelae of missing GABHS pharyngitis are potentially significant. It is estimated that 3000 to 4000 patients with GABHS need to be treated to prevent one case of rheumatic fever. Because the clinical diagnosis of viral versus bacterial pharyngitis is difficult to make, several prediction rules have been proposed. A recent study in the Journal of Pediatrics demonstrated that most clinical prediction rules are both sensitive and specific in differentiating between viral and bacterial pharyngitis. This distinction is useful in decreasing the inappropriate use of antibiotics in sore throat.

The clinical prediction rule from the Centers for Disease Control and Prevention (CDC) recommends screening adults for the following criteria: history of fever, absence of cough, tonsillar exudates, and tender anterior cervical adenopathy. According to the CDC, patients who do not meet any of these criteria should not be treated with antibiotics. If the patient has two or more, any one of three treatment strategies is acceptable: a rapid strep test with antibiotic treatment only for those with a positive result; a rapid strep test with antibiotic treatment for those with a positive result and those with all four criteria; or empiric antibiotic treatment for any patient with three or more criteria with no diagnostic testing.

Streptococcal pharyngitis is much more common in the pediatric population; it is found in 24% to 36% of children with sore throat. Therefore, the CDC recommends that a rapid strep test be performed in all pediatric patients presenting with sore throat. Treatment is indicated with a positive result, as is follow-up culture evaluation with a negative result.

Preliminary studies show that the rapid strep test along with clinical pretest probability may be equal to culture results in identifying streptococcal infections in all patients. However, a definitive study has yet to be done. Cultures are not recommended in the adult population unless an alternative bacterial diagnosis (such as gonococcal pharyngitis) is considered likely.

Antibiotic therapy (see tables below) reduces the duration of symptoms by about one or two days if begun within three days of symptom onset. However, the true benefit of appropriate antibiotic treatment is the prevention of long-term sequelae of streptococcal infection (such as acute rheumatic fever).?The antibiotic of choice for GABHS is still penicillin (500 mg twice daily in adults, 25 to 50 mg/kg/day divided into three doses in children), since the United States has no group A Streptoccocus strains that are resistant to penicillin. Injectable penicillin (benzathine penicillin administered intramuscularly) was the original antibiotic studied in the 1950s for the eradication of GABHS and remains a valuable treatment today. Oral penicillin, amoxicillin, and certain cephalosporins appear to have comparable eradication rates to intramuscular benzathine penicillin.

While penicillin remains the recommended antibiotic, oral amoxicillin is frequently used in young children because its improved taste makes it easier to administer and its efficacy appears equal to that of penicillin. Recent studies have shown that once-daily dosing of amoxicillin may be an acceptable alternative as well.

For all patients in whom antibiotic compliance is questionable, an intramuscular injection of benzathine penicillin may be the best treatment option. In penicillin-allergic patients, erythromycin is recommended, although azithromycin is frequently used. Azithromycin has an improved side effect profile (reduced gastrointestinal effects) and a treatment plan approved by the Food and Drug Administration that calls for once-daily dosing for five days. Clarithyromycin is also an alternative in penicillin-allergic patients. Most other antibiotics require 7 to 10 days of treatment to fully eradicate the infection.


SYMPTOM RELIEF

A recent study in the Annals of Family Medicine found that patients who request antibiotics for acute pharyngitis do so because they believe the drugs will provide pain relief. Therefore, if adequate pain relief is provided for viral pharyngitis, patient satisfaction will increase and inappropriate requests for antibiotics may be avoided. Many remedies are suggested for pain relief in acute pharyngitis, including liquid acetaminophen, a liquid acetaminophen/codeine mixture, and ibuprofen. In addition, salt water gargles, made by mixing one teaspoon of salt in one quart of warm water, and a diet of cool, soft foods such as gelatin and ice cream are commonly used to improve symptoms. Herbal teas containing demulcents have also been used for short-term relief of symptoms. A demulcent is anything that soothes; common examples used for sore throats are licorice and mallow root.

Very few studies have evaluated these home remedies. One study in the Journal of Alternative and Complementary Medicine found that an herbal tea called Throat Coat, containing common demulcents, provided better short-term pain relief than regular tea alone. Another study found that gargles of ketoprofen lysine salt mouthwash, an anti-inflammatory, subjectively reduced pain better than gargles of a topical anesthetic.

Inflammation plays a significant role in the pain caused by pharyngitis. A commonly accepted practice is to provide steroids to counteract the inflammation and provide symptomatic relief of severe sore throats. The steroids dexamethasone and betamethasone can be given either intramuscularly or by mouth. Most studies recommend one dose of steroids (0.6 mg/kg dexamethasone, up to a maximum dose of 10 mg) given on diagnosis. A review of the literature finds that steroids do improve pain in acute pharyngitis and that oral dexamethasone is equally as effective as dexamethasone administered intramuscularly. However, if the patient complains of significant pain with swallowing, then perhaps the intramuscular route would be preferred. Intramuscular toradol is an excellent alternative. Oral narcotics, such as codeine, are often used for pain relief, but the efficacy of these drugs in relieving sore throat remains unproven.


PERITONSILLAR ABSCESS: ANATOMY, DIAGNOSIS, AND TREATMENT


In order to accurately diagnose and treat a PTA, a review of the relevant anatomy is in order. The palatine tonsils lie in the interval between the palatoglossal and palatopharyngeal arches, an area referred to as the tonsillar bed. The superior constrictor of the pharynx forms the base of the tonsillar bed, and the junction of the pharyngobasilar fascia and the periostium of the skull base form its superior limits. Each vascularly rich tonsil receives its blood supply from the tonsillar artery, a branch of the facial artery, which enters at the tonsil’s inferior pole. The external palatine vein, however, is generally the culprit when excessive bleeding is noted during tonsillectomy or PTA drainage. This large vein descends along the lateral surface of the tonsil before joining the pharyngeal venous plexus. While these vessels must be considered when performing procedures in the region of the palatine tonsils, a more important consideration is the proximity of the internal carotid artery, which lies approximately 2.5 cm laterally and posteriorly to the tonsil.

Peritonsillar abscesses are generally diagnosed in teenagers and young adults. The diagnosis is rarely made in patients under six years of age or over age 65. If, after the history and physical exam, the diagnosis of PTA is still unclear, imaging studies may be of some value. Ultrasound may be performed transcutaneously or intraorally to evaluate for an abscess. A recent study suggests that the use of ultrasound in the emergency department can assist with the diagnosis of PTA and reduce complications associated with drainage. Computed tomography (CT) scanning with intravenous contrast can also help to delineate the affected area and evaluate for abscesses and is the imaging study of choice. Another benefit to CT scanning is the likely visualization of an alternative diagnosis if a PTA is not present.

Commonly accepted treatments for PTA include needle aspiration and drainage, incision and drainage, or immediate tonsillectomy (also known as a “quincy tonsillectomy”), which requires the skills of a surgeon. The once-common tonsillectomy has fallen out of favor. In fact, a single episode of PTA is no longer considered an indication for tonsillectomy; rather, the trend today is toward outpatient management with surgical drainage and antibiotics. Needle aspiration and drainage versus incision and drainage remains an area of controversy. Several studies have been done comparing the two procedures, but most lack the power to make a convincing statement in support of one or the other. A recent review performed by Johnson suggests that while incision and drainage has a slightly higher success rate, (93.7% versus 91.6%), needle aspiration is less painful. The recurrence rate is similar for both procedures (about 10%).

An argument could be made in favor of needle aspiration because of the lower risk of serious internal carotid artery injury. Puncturing the carotid artery with a needle will not cause as much bleeding as lacerating it with a scalpel.


PROPER TECHNIQUE

To perform needle aspiration and drainage, you’ll need a cooperative patient sitting in an upright position under good lighting. (Consider wearing a headlamp for better illumination of the oral cavity.) Administering a mild sedative or analgesic prior to the procedure should make the patient feel more comfortable. Topical anesthesia with benzocaine spray or lidocaine is recommended. Intraoral lidocaine can also be instilled to further anesthetize the area, using a 27-gauge needle and 1 to 2 ml of 1% lidocaine. A Yankauer suction catheter attached to low wall suction can be given to the patient to remove any oozing purulent discharge during the procedure.

For aspiration of the PTA, an 18-gauge sharp needle should be attached to a 20-ml syringe. A needle guard can prevent the needle from penetrating too deeply, protecting the carotid artery from puncture. To create a guard, cut the cap of the needle 1 cm from the needle’s end and replace the cap. After retracting the patient’s cheek laterally to maximize visibility, insert the needle no more than 1 cm into the most prominent area of the abscess. Be careful not to advance the needle laterally toward the carotid artery.

If the aspiration is positive, remove as much purulent discharge as possible. If it is negative, an attempt may be made to aspirate the middle and inferior poles of the tonsil. About 30% of abscesses will be missed if only the superior pole is aspirated.

Following a positive aspiration, antibiotic treatment is recommended for eradication of the offending organisms. Clindamycin 500 mg twice daily or a second- or third-generation cephalosporin is the preferred antibiotic choice. Penicillin was once very effective, but with increased microbial resistance it is no longer a viable option. If a patient has a PTA that cannot be easily drained in the emergency department, an otolaryngology consultation is indicated for definitive treatment.