Incidence

1. Pharyngitis is the fourth most common condition seen in medical practice. Group A streptococcus accounts for approximately 5% to 15% of adults who present for evaluation and treatment for pharyngitis. Viral pharyngitis accounts for approximately 40% to 60% of all cases of sore throat.

Pathogenesis

1. Pharyngitis may be due to viral, bacterial, and fungal agents, as well as other atypical agents:
   1. Viral agents include rhino/adenoviruses, coxsackie-virus, enteric cytopathic human orphan (ECHO) viruses, and Epstein–Barr virus.
   2. Bacterial agents include Group A beta-hemolytic streptococcus (GAS), Neisseria gonorrhoeae, and Corynebacterium diphtheriae.
   3. The fungal source is Candida albicans.
   4. Atypical agents includeMycoplasma pneumoniae and Chlamydia trachomatis (rare).
   5. Noninfectious causes include allergic rhinitis, postnasal drip, mouth breathing, mechanical/caustic agents, and trauma.

Predisposing Factors

1. Cigarette smoking.
2. Allergies.
3. Upper respiratory infections.
4. Oral sex.
5. Drugs (antibiotics and immunosuppressants).
6. Debilitating illnesses (such as cancer) that can cause C. albicans to proliferate.

Common Complaints

1. Sore and/or scratchy throat.
2. Fever.
3. Headache.
4. Malaise.

Other Signs and Symptoms

1. Oral vesicles.
2. Exudate on throat.
3. Lymphadenopathy.
4. Fatigue.
5. Dysphasia, hoarseness.
6. Abdominal pain.
7. Vomiting.

Potential Complications

Without proper antimicrobial treatment, streptococcal pharyngitis can lead to serious complications such as the following:

1. Suppurative adenitis with tender, enlarged lymph nodes.
2. Scarlet fever.
3. Peritonsillar abscess.
4. Glomerulonephritis.
5. Rheumatic fever.

Subjective Data

1. Ask the patient about onset, course, and duration of symptoms. Ask about dyspnea or dysphagia.
2. Inquire about mouth lesions, rhinorrhea, cough, drooling, and fever.
3. Ask about malaise, headache, fatigue, and fever; these are symptoms of mononucleosis.
4. Take a sexual history, if indicated. Ask if family members or sexual partners have the same signs and symptoms. Pharyngeal gonorrhea has no symptoms, so high-risk patients should be tested.
5. Ask whether symptoms have caused decreased intake of food and fluid.
6. Determine history of heart disease; previous strep pharyngitis; rheumatic fever; and other respiratory diseases, such as asthma, emphysema, and chronic allergies.
7. If rash is present, find out when it first occurred and if it has spread.
8. Ask about signs and symptoms of urinary tract infection and pyelonephritis.
9. Ask about a history of herpes, immunosuppressive disorders, and steroid use.
10. Review immunization history.

Physical Examination

1. Temperature and blood pressure, if indicated.
2. Inspect:
   1. Observe general appearance.
   2. Examine the mouth, pharynx, tonsils, and hard and soft palate for vesicles and ulcers, candidal patches, erythema, hypertrophy, exudate, and stomatitis. Check gum and palate for petechiae and tongue for color and inflammation.
   3. Examine the ears, nose, and throat. Assess patency of airway if tonsils are enlarged.
   4. Inspect skin for rashes:
      1. Pastia’s lines are petechiae present in a linear pattern along major skin folds in axillae and antecubital fossa that are seen with Group A streptococcus.
      2. Erythema marginatum, caused by Group A streptococcus, is an evanescent, nonpruritic, pink rash mainly on the trunk and extremities. It may be brought out by heat application.
3. Auscultate: Auscultate heart and lungs.
4. Percuss:
   1. Percuss abdomen, especially spleen area.
   2. Percuss chest.
5. Palpate:
   1. Palpate lymph nodes, especially of the anterior and posterior cervical chains, axilla, and groin.
   2. Palpate abdomen for organomegaly and suprapubic tenderness.
   3. Palpate back for costovertebral angle (CVA) tenderness.
6. Neurologic exam: Check for nuchal rigidity and meningeal irritation.
7. Use Modified Centor Clinical Prediction Rule for Group A streptococcal infection:

   Points	Criteria
   +1	Tonsillar exudates present
   +1	Tender anterior chain cervical adenopathy
   +1	Absence of a cough
   +1	Fever by history
   +1	Less than 15 years of age
   0	Age is 15 to 45 years of age
   -1	Greater than 45 years of age
   Total Score

   
   Once scored:
   If 4 points, + predictive value of 80%, treat empirically.
   If 2 to 3 points, positive predictive value of 50%, complete rapid strep antigen, treat as Group A beta-hemolytic Streptococcus (GAS) positive.
   If 0 or 1 point, positive predictive value of 20%, do not test, treat empirically only with follow-up as needed.

Diagnostic Tests

1. Rapid strep test; if negative, then perform throat culture and sensitivity. Throat culture and sensitivity is the gold standard for diagnosis.
2. Monospot test.
3. Complete blood count (CBC) with differential.
4. Gonorrhea culture.
5. Blood cultures if sepsis is suspected.
6. Radiograph of neck if possible trauma.

Differential Diagnoses

1. Pharyngitis.
2. Stomatitis.
3. Rhinitis.
4. Sinusitis with postnasal drip.
5. Epiglottis.
6. Peritonsillar abscess.
7. Mononucleosis.
8. Herpes simplex.
9. Coxsackie A virus.
10. C. diphtheriae.
11. Trench mouth.
12. Vincent’s angina.
13. C. albicans.
14. HIV.

Plan

1. General interventions:
   1. Patients with a history of rheumatic fever and those who have a household member with a documented Group A streptococcal infection need immediate treatment without prior testing.
   2. Herpangina are small oral vesicles on the fauces and soft palate caused by the coxsackievirus.
   3. Herpes causes vesicles and small ulcers (stomatitis) of the buccal mucosa, tongue, and pharynx.
   4. Trench mouth (gingivitis) and necrotic tonsillar ulcers (Vincent’s angina) cause foul breath, pain, pharyngeal exudate, and a gray membranous inflammation that bleeds easily.
   5. C. albicans (thrush) may be painful and causes cheesy, white exudate.
   6. Oral candidiasis may be the first symptom of HIV.
   7. Peritonsillar cellulitis causes inflamed, edematous tonsils, grayish-white exudate, high fever, rigors, and leukocytosis. Peritonsillar abscess (palpable mass) may also develop.
   8. Mononucleosis causes tonsillar exudates in 50% of patients; 33% develop petechiae at junction of hard and soft palate.
   9. C. diphtheriae causes a whitish-blue pharyngeal exudate “pseudomembrane” that covers the pharynx and bleeds if removal is attempted.
   10. Do not put instruments in the airway if you suspect epiglottitis.
2. See Section III: Patient Teaching Guide “Pharyngitis”.
3. Pharmaceutical therapy:
   1. Drug of choice: Prescribe one of the following penicillins for bacterial pharyngitis:
      1. Penicillin V potassium (Pen-Vee-K): 500 mg twice a day for 10 days.
      2. Amoxicillin: 500 or 875 mg twice a day for 10 days.
      3. Penicillin G benzathine: 1.2 million units intramuscular injection, one dose.
      4. Cephalexin: 500 mg twice a day for 10 days.
   2. If the patient is allergic to penicillin:
      1. Clindamycin: 600 mg three times a day for 10 days.
      2. Azithromycin: 500 mg on day 1 followed by 250 mg daily on days 2 to 5.
      3. Clarithromycin: 250 mg twice a day for 10 days.
   3. Recurrent bacterial pharyngitis:
      1. Clindamycin: 600 mg three times a day for 10 days.
      2. Penicillin and rifampin: Penicillin V: 500 mg twice a day for 10 days.
      3. Amoxicillin–clavulanic acid: 500 mg every 8 hours or every 12 hours for 10 days; or 875 mg every 12 hours for 10 days; not for use in creatinine clearance less than 30 mL/min.
      4. Penicillin G benzathine: 1.2 million units intramuscular injection, plus one dose rifampin 600 mg/d orally for 4 days.
   4. For pharyngeal gonorrhea: Ceftriaxone (Rocephin) 500 mg to 1 g by intramuscular (IM) injection (provider should prescribe to cover for C. trachomatis as well).
   5. For Mycoplasma pneumoniae and C. trachomatis: Erythromycin (E-Mycin) 250 mg orally three to four times daily for 10 days or azithromycin 1 g orally single dose or doxycycline 100 mg orally twice/day for 7 days.
   6. For pharyngeal candidiasis in the immunocompromised patient:
      1. Oral nystatin suspension (100,000 U/mL): 15 mL by swish-and-swallow method four times a day.
      2. Clotrimazole troche: 10 mg held in mouth 15 to 30 minutes three to five times daily for 7 to 10 days.

Follow-Up

1. If symptoms do not improve in 3 to 4 days, recheck patient.
2. Treat sexual partners of patients with pharyngeal gonorrhea.

Consultation/Referral

1. Consult physician/specialist if patient has severe dysphagia or dyspnea, signaling possible airway obstruction.
2. Refer the patient to an otolaryngologist if peritonsillar abscess is noted.

Individual Considerations

1. Recommendations include treating patients with oral antibiotics for 10 days to eradicate infection. For patients who are not able to tolerate oral antibiotics, penicillin G benzathine may be given via intramuscular route.
2. Geriatrics:
   1. Acetaminophen for sore throat is treatment of choice for geriatric population.
   2. Antibiotic treatment for pharyngitis is warranted if patient is ≥65 years old with an acute cough and has two or more of the following criteria: hospitalized in the past year, diabetic, congested heart failure, on glucocorticoid therapy. If the patient is ≥80 years old with pharyngitis and a cough, then treat with antibiotic if one or more of the latter criteria applies.
   3. Elderly patients with chronic illnesses (such as diabetes, congested heart failure, and skin diseases) that have pharyngitis caused by Group A streptococci are at an increased risk of bacteremia and more likely to die from complications.