Topic Editor: Becky Box, MBBS
Review Date: 9/12/2012
Definition 
- Acute pharyngitis is the rapid onset of pharyngeal inflammation and pain. It can encompass the entire pharynx or be isolated to the nasopharynx, oropharynx or laryngopharynx
- Infectious diseases are the most common etiological agent identified in acute pharyngitis
- Other common causes include:
- Chemical exposure/irritation
- Foreign body reaction
- Systemic inflammatory disorders (Kawasaki disease, Steven Johnson's syndrome)
Description
- Inflammation/infection of the pharynx most often caused by acute viral infection
- The most important cause of bacterial pharyngitis in school aged children is Group A beta Hemolytic Streptococci (GABHS)
- Infection is typically transmitted by respiratory droplets due to close contact; with children being the most frequent reservoir of infection
- Rapid antigen detection tests give immediate point-of-care assessment whether GABHS is the cause of a case of pharyngitis
- The aim of treatment is to:
- Identify and treat cases caused by a bacterial cause (usually GABHS)
- Treat symptoms (pain/fever)
- Reduce risk of complications from untreated GABHS infection (glomerulonephritis, rheumatic fever, etc)
- Reduce severity and duration of symptoms
- Reduce transmission of illness
Epidemiology
Incidence/Prevalence
- 1-2% of both General Practice and Emergency department presentations are due to sore throat
- The true incidence of non-infectious causes of sore throat has been poorly studied. Generally speaking, viral infection is felt to represent approximately 85% of infectious cases
- On average, upper respiratory tract infections, which commonly include pharyngitis symptoms, occur 2-4 times/year in adults and 4-8 times/year in children depending upon age and exposures
- Viral agents causing pharyngitis more frequently in the colder months
- Group A strep is the most common bacterial cause of Pharyngitis in School-aged children
Age
- Pharyngitis is more common in children, with approximately 15-30% in school aged children, and ~10% in adults being due to GABHS
- Viral etiology is the most common cause in infants and pre-school aged children
- GABHS pharyngitis is rare in children under 2 years of age, with the incidence peaking in primary-school-aged children
- While GABHS remains common in older children and young adults, other bacterial causes, such as fusobacterium, gonorrhea, and mycoplasma also contribute to bacterial etiology
Risk factorsRisk Factors associated with increased transmission rates:
- Age: Younger people are more susceptible
- Close quarters
- Fatigue
- GABHS infected contact
- History of radiotherapy to region
- Immunocompromised host
- Poor hygiene
- Nasal Colonization with GABHS
- Risk Factors associated with the host such as diabetes mellitus, excessive alcohol consumption
- Sexual activity or abuse (pharyngitis associated with STI organisms)
- Smoking
Etiology
- Viral organisms are the most commonly implicated infectious organisms causing acute pharyngitis
- Bacterial causes, such as GABHS, are less common, but can be associated with complications, with patients generally benefitting from early antimicrobial treatment
- Adenovirus & Coronavirus account for up to 40% of the viral causes for acute pharyngitis. Other common viral causes include Rhinovirus, Coxsackievirus, Herpes Simplex Virus, Parainfluenzae, Influenzae, Cytomegalovirus, Epstein-Barr Virus and Human Immunodeficiency Virus
- GABHS is the most common bacterial cause of pharyngitis. It is transmitted by respiratory droplets, particularly in winter months, but accounts for less than one-third of all causes of acute pharyngitis
- Other bacterial causes include:
- Fusobacterium
- Group C or G Streptococci
- Mycoplasma species
- Arcanobacterium haemolyticum
- Non-infectious causes of acute pharyngitis include:
- Chemical inhalation or ingestion
- Gastroesophageal reflux
- Irritant exposure
- Sinusitis (post nasal drip with inflammation)
- Systemic inflammatory conditions
- Trauma
[Outline]
History
- The history is a key differentiator between both the type of infectious agent (bacterial/viral) and also non-infectious causes. Unfortunately, there is significant overlap between symptoms and causative agent
- Viral etiology will usually be associated with typical prodromal symptoms and include coryzal symptoms, cough, conjunctivitis, myalgia, arthralgia, headache, sore throat, and fever
- Bacterial infections, particularly GABHS are associated with significant fever, and an absence of viral upper respiratory tract infection symptoms
- Time of year and the age of the patient also relates to probability of bacterial versus viral etiology (winter or early spring and younger age have increased risk of GABHS)
- Inflammatory conditions which present with sore throat will have other identifying features, such as a vasculitis, rash, arthritis, arthralgias, and other organ system involvement
- Traumatic or chemical exposure related cases should be elicited from the history
Physical findings on examination
The classic triad of features with infectious pharyngitis includes:
- Sore throat
- Pharyngeal edema/swelling
- Fever
Additional findings on physical examination help distinguish between causative organisms:
Viral Pharyngitis
- Many viral infections will present with cough, conjunctivitis, diarrhea, and/or coryzal symptoms
- Features on physical examination that may implicate a specific virus include:
- Enteroviruses-Vomiting/diarrhea, erythematous rash and conjunctivitis. Coxsackievirus is an Enterovirus, which can present with herpangina and/or hand, foot and mouth disease
- Adenoviruses-Pharyngitis and conjunctivitis, with fever, most commonly in the summer months. The pharyngitis is generally exudative
- Herpes Simplex Virus-Cervical lymphadenopathy, gingivostomatitis and ulcerative lesions of the buccal mucosa and lips, usually sparing the posterior pharynx
- Epstein-Barr Virus- Lymphadenopathy, hepatosplenomegally and less commonly a rash of variable morphology (~10% of patients). Incidence of rash increases to 90%, when patients are inappropriately treated with amoxicillin
Bacterial Pharyngitis- GABHS usually presents with rapid onset of fever, with headache, and sore throat. It is not unusual to have nausea, vomiting and/or abdominal pain. Usually there is an absence of coryzal symptoms
- Features on examination which may implicate a specific bacterial cause include:
- GABHS-Pharyngeal exudate, scarlatiniform rash (in strains that produce erythrogenic toxin) and cervical lymphadenopathy
- Corynebacterium diphtheria-The distinct finding on physical examination of a grayish brown pseudomembrane that bleeds readily with attempted removal. There may be diffuse swelling of the subcutaneous tissues leading to ‘bull neck' and stridor. Complete airway obstruction can occur, depending on the extent of the membrane
- Atypical bacteria-Mycoplasma or Chlamydia pneumoniae can cause lower respiratory tract findings, and at time pharyngitis, which can have tonsillar exudate and adenopathy
- Neisseria gonorrhoeae, group G & C streptococcal infection, fusobacterium, and Arcanobacterium hemolyticum can all have similar physical findings to GABHS pharyngitis
- Centor Score, for prediction of GABHS Pharyngitis:
- The Centor score is one tool developed to assess the probability of GABHS pharyngitis being present
- The score includes the following four criteria
- History of fever-1 point
- Tonsillar exudates-1 point
- Tender anterior cervical lymphadenopathy-1 point
- Absence of cough-1 point
- The modified criteria adds 1 point for age 4-15 and subtracts 1point for age >44 years
- The presence of all four variables has a positive predictive value of 40-60% for the presence of a positive throat culture for Group A streptococcus vacteria. The absence of all four gives a negative predictive value > 80%
- Guidelines for clinical management based on the Centor scoring system are as follows:
- 2 points-no antibiotic treatment or throat culture indicated
- 2-3 points-throat culture and treatment if positive
- > 3 points-treat empirically
[Outline]
Other laboratory test findings
- The clinical course of virtually all viral pharyngitis is benign. In such cases, testing is rarely indicated. In limited cases HSV culture/PCR, monospot and/or EBV titers, CMV titers, or HIV testing can be indicated
- GABHS rapid antigen detection test (RAT) and throat culture:
- Compared with throat swab, RAT has a 95% sensitivity and specificity for the diagnosis of Group A streptococcus pharyngitis
- In patients with high likelihood of streptococcal infections (Centor criteria
3), if RAT is available, it should be considered to confirm the diagnosis- particularly in children where the incidence of GABHS is higher - In patients with low Centor score (0-2) the routine use of RAT is not indicated
- If RAT for Group A streptococcus is negative, a throat culture is indicated in children and adolescents, but not in adults (as the incidence of GABHS is lower as are risks for complications). Culture can also rarely be indicated to exclude an alternate bacterial cause of pharyngitis
- Testing is unnecessary in children 3 years of age unless they have an older sibling with GABHS infection of other risk factors
- Polymerase chain reaction for GAS:
- Equal to throat culture in sensitivity and specificity but gives more rapid results
- This test is more expensive than culture or RAT, and is not routinely used
General treatment items
- Viral infections are generally self-limited and require only symptomatic treatment
- GABHS is also self-limited condition, in which the fever and throat pain start to improve, on average within 3-4 days without antimicrobial therapy
- Use of antimicrobial therapy for GABHS generally results in only a modestly more rapid (24 hours) improvement in symptoms as compared to no antibiotics
- Treatment of GABHS reduces the rate of disease transmission and development of suppurative complications, such as glomerulonephritis or acute rheumatic fever
- Antibiotic therapy should be reserved for patients with microbiologically confirmed GABHS, and should not be based on a clinical diagnosis only
- In the event pharyngitis symptoms are not improving with 3-4 days of antibiotic therapy, consideration of alternate diagnoses should be considered
- Anesthetic sprays and salt water gargling may provide some analgesia
- Analgesics (acetaminophen and/or ibuprofen) have been shown to be better than placebo in reducing acute sore throat pain in adults
- Aspirin should be avoided in children due to its association with Reye syndrome
- Use of corticosteroids for symptomatic treatment of GABHS pharyngitis is controversial. Some data indicates more rapid improvement as compared to no use of corticosteroid. In more severe cases, corticosteroids may be reasonable
- There is currently no substantial evidence to support the use of herbal remedies or acupuncture in the treatment of acute pharyngitis
1) Acute pharyngitis with confirmed GABHS
- Antibiotic therapy should be reserved for patients with microbiologically confirmed GABHS pharyngitis (a positive rapid antigen test or culture) and not based on a clinical diagnosis only
- If pharyngitis symptoms are not improving with 3-4 days of antibiotic therapy, alternate diagnoses should be considered
- Early initiation of antimicrobial therapy results in more rapid resolution of signs and symptoms
- Antibiotics decrease the likelihood of local suppurative complications and acute rheumatic fever
- Oral penicillin V or amoxicillin for 10 days is the preferred treatment in non-penicillin allergic patients
- For patients who are unable to complete a 10 day oral course of penicillin V, a single IM dose of penicillin G benzathine can be administered
- Other antibiotic options in include, a first generation cephalosporin such as cephalexin or cefadroxil, clarithromycin, azithromycin, or clindamycin
- In patients with recurrent symptoms, retreatment with a first-line agent is appropriate (oral penicillin, benzathine penicillin, amoxicillin, a first generation cephalosporin such as cephalexin or cefadroxil, clarithromycin, azithromycin, or clindamycin)
- In resistant cases, sensitivities may be required. Clindamycin may be recommended in such cases
2) Acute pharyngitis with diphtheria
- Pharyngeal diphtheria is extremely rare in the U.S.
- When there is strong clinical suspicion of diphtheria, diphtheria antitoxin and penicillin should be administered as a matter of urgency
- Patients with diphtheria can deteriorate rapidly, so laboratory confirmation of the diagnosis should not delay treatment
- The treatment is both the initiation of prompt antibiotic coverage to eradicate the organism (penicillin V, IM penicillin, or erythromycin) and use of diphtheria antitoxin
- Antibiotics hasten recovery and prevent the spread of the disease to other individuals
3) Acute pharyngitis with tularemia
- Regular isolation practices should be followed
- Regardless of the clinical manifestation, antibiotics which treat Francisella tularensis is critically important
- Drugs of choice include gentamicin, tobramycin or streptomycin. Ciprofloxacin or doxycycline are alternatives
4) Acute gonococcal pharyngitis
- Oral cephalosporins have no proven efficacy, but may be effective
- Ceftriaxone is the drug of choice as a single intramuscular injection
5) Acute pharyngitis with infectious mononucleosis
- Treatment should be focused on the control of symptoms, including use of analgesics and topical throat sprays
- Patients should be warned against vigorous activities that might produce splenic rupture during the first month, or longer if splenic enlargement persists, after the onset of illness
- Corticosteroids (prednisone or dexamethasone) produce symptomatic improvement, but their use in what is a benign and self-limited illness is not usually recommended. In cases with significant tonsillar swelling and/or concerns regarding impending airway obstruction, severe thrombocytopenia, or hemolytic anemia, steroids may be indicated
- Intravenous immunoglobulin (IVIG) may be used in patients with immune thrombocytopenia
6) Acute pharyngitis from candida (Thrush)
- Oral candidiasis (mild to moderate cases) may be treated with nystatin or clotrimazole. It is recommended to continue therapy for at least 48 hours after symptoms have completely resolved
- For patients with more significant involvement, an antifungal such as fluconazole may be more effective
7) Acute pharyngitis with herpetic stomatitis
- In immunocompromised hosts, antiviral agents drugs decrease pain and viral shedding and accelerate healing of lesions. In cases where there is no immunocompromise, use of antiviral agents is common; the evidence for this practice is less established
- Treatment should be initiated within 48 to 72 hours of onset of signs or symptoms
- For active disease, acyclovir, valacyclovir, or famciclovir are suitable
- The length of therapy for immunocompetent patient is typically 5-7 days, but for immunocompromised patients usually extends until all lesions are resolved
Medications indicated with specific doses
Antipyretics/analgesics
- Acetaminophen [Oral]
- Ibuprofen
Antibiotics - Amoxicillin
- Azithromycin
- Cefadroxil
- Ceftriaxone
- Cephalexin
- Ciprofloxacin
- Clarithromycin
- Clindamycin
- Doxycycline
- Gentamicin
- Penicillin G benzathine
- Penicillin V
- Streptomycin
- Tobramycin
Antifungal- Clotrimazole
- Fluconazole
- Nystatin
Antiviral- Acyclovir
- Famciclovir
- Valacyclovir
CorticosteroidsImmunoglobulin (IVIG)[Non-FDA Approved]- Adult Dosing: 400 mg/kg/day for 2-5 days
Dietary or Activity restrictions
- As tolerated; encourage the consumption of fluids
Disposition
Admission Criteria
- Severe dehydration
- Airway compromise
- Suspected child abuse
- Signs or symptoms of systemic infection indicating bacteremia
Discharge Criteria- Tolerating oral intake
- Hemodynamically stable
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