Basics
Description
Pharyngitis specifically refers to inflammation of the pharynx as indicated by erythema and swelling of the structures in the posterior portion of the oral cavity including the tonsillar pillars, the tonsils, the inferior soft palate, the uvula, and the posterior wall. Pharyngitis is usually caused by viral or bacterial infections.
Epidemiology
- Prevalence and etiology of pharyngitis vary based on age of patient and time of year.
- In preschool-aged children, viral agents are most common and exhibit seasonal variation depending on the specific virus.
- Group A Streptococcus (GAS) pharyngitis is most common in children between the ages of 5 and 15 years, is very rare in children younger than the age of 3 years, and may occur in outbreaks affecting up to 20% of children at risk.
- Pharyngitis caused by Neisseria gonorrhoeae occurs primarily in sexually active adolescents.
Etiology
- Viral
- Common causes: adenovirus, Epstein-Barr virus (EBV), influenza A and B, enteroviruses (specifically, coxsackievirus A), herpes simplex virus (especially in adolescents), and echoviruses
- Uncommon: measles, rubella, cytomegalovirus, human immunodeficiency virus (HIV)
- Rhinovirus, coronavirus, parainfluenza virus, and respiratory syncytial virus (RSV) may cause sore throat but not usually pharyngitis.
- Bacterial
- Common: Streptococcus pyogenes (group A ²-hemolytic Streptococcus)
- Uncommon: Mycoplasma pneumoniae, group C or G streptococci, N. gonorrhoeae (more likely in sexually active adolescents), Arcanobacteriumhaemolyticum, Fusobacterium necrophorum (Lemierre syndrome), Corynebacterium diphtheriae (diphtheria), Chlamydophila pneumoniae, Chlamydophila psittaci, Yersinia enterocolitica, Treponema pallidum (syphilis), Francisella tularensis (tularemia), oral anaerobes (Vincent angina or trench mouth)
- Fungal: Candida species (oral thrush)
General Prevention
- Most infectious agents that cause pharyngitis are spread through contact with respiratory droplets or other body fluids, although many can live for some time outside of the body.
- Careful hand washing and avoiding respiratory secretions are key to minimizing transmission.
- Return to school/child care
- Children diagnosed with GAS pharyngitis should be kept at home for 24 hours after starting antibiotics.
- Children with pharyngitis due to presumed viral etiology should be fever-free for 24 hours and have symptoms under control prior to return.
Risk Factors
- Children who are immunocompromised and children on chronic inhaled corticosteroids who are otherwise immune competent are at risk for candidiasis of the pharynx.
- Adolescents or sexually abused children engaging in oral sex are at risk for pharyngitis due to gonorrhea or HSV.
- Unvaccinated patients or travelers from certain areas are at risk for vaccine-preventable diseases: diphtheria and measles.
Diagnosis
History
- Typical: sore throat, fever
- Variable
- Headache, nausea, vomiting, abdominal pain (suggest GAS pharyngitis)
- Rhinorrhea, cough, hoarseness, stridor, conjunctivitis (suggest viral etiology)
- Rash: scarlatiniform or nonspecific viral
- Sudden onset of fever and sore throat with difficulty swallowing, headache, stomach pain, nausea, vomiting, or scarlatiniform rash support diagnosis of GAS pharyngitis.
- Pharyngitis associated with rhinorrhea, cough, hoarseness, conjunctivitis, diarrhea, or nonspecific rash is more likely to have a viral cause.
- Significant systemic complaints such as fever and malaise are characteristic of EBV or HIV (acute retroviral syndrome).
- History of oral sex suggests possibility of N. gonorrhoeae infection.
Physical Exam
- Pharynx and oral cavity
- Exudative tonsillitis suggestive of GAS but also present in EBV, N. gonorrhoeae, Arcanobacterium, HSV, adenovirus
- Palatal petechiae suggest GAS.
- Ulcers on tonsils or tonsillar pillars seen in coxsackievirus, HSV, echovirus
- Ulceration or inflammation of buccal mucosa or gums seen in HSV, coxsackievirus
- Lymph nodes
- Tender anterior lymphadenopathy more common in GAS pharyngitis
- Diffuse LAD, splenomegaly suggests EBV.
- Rash
- Scarlatiniform rash (diffuse, erythematous, fine-papular, "sandpapery " rash) key feature of scarlet fever from GAS pharyngitis but can be seen with Arcanobacterium haemolyticum and in Kawasaki disease
- Nonspecific, diffuse rash can be associated with viral infection; may be seen shortly after starting antibiotic if underlying etiology is EBV
- Vesicular lesions on hands, feet, and/or buttocks characteristic of coxsackievirus
Diagnostic Tests & Interpretation
Lab
- Rapid antigen detection test (RADT)
- The diagnosis of GAS pharyngitis should not be made based on clinical features alone but should be confirmed by laboratory testing.
- Sensitivity varies (55 " 90%) based on quality of sample obtained. Specificity is more consistent in 95 " 98% range. Therefore, a good test to rule in GAS, but culture or DNA probe should be used to confirm negative RADTs. Confirmation of positive RADTs is not needed.
- RADT is not recommended when patients present with symptoms that strongly suggest viral etiology (cough, rhinorrhea, hoarseness, oral ulcers).
- Testing children <3 years old is not indicated, as those children are at very low risk for acute rheumatic fever (ARF). Testing may be considered in this age group if other risk factors are present such as an older sibling with GAS.
- Testing of asymptomatic household contacts is not recommended.
- Monospot (heterophile antibody) test
- Detects presence of IgM for EBV, which appears during the first 2 weeks of illness and gradually disappears over 6 months
- Atypical lymphocytes may also be seen on WBC differential during the 2nd week of EBV infection. >10% atypical lymphocytes plus a positive heterophile antibody test is diagnostic of acute infection.
- Heterophile antibody is often negative in children <4 years of age with EBV, so it should not be used in this age group.
- Testing for certain bacteria (N. gonorrhoeae, A. hemolyticum, F. necrophorum) requires special handling and processing, so must confirm appropriate collection medium and alert the laboratory performing the test if any of these agents is suspected.
Differential Diagnosis
- Infectious
- Peritonsillar or retropharyngeal abscess or cellulitis
- Lemierre syndrome
- Epiglottitis
- Kawasaki disease
- Tularemia
- Ingestions
- Caustic or irritant ingestions
- Inhaled irritant
- Tumors
- Leukemia
- Lymphoma
- Rhabdomyosarcoma
- Trauma: vocal abuse from shouting
- Allergy: potnasal drip from allergic rhinitis
- Miscellaneous
- PFAPA syndrome (periodic fever, aphthous ulcers, pharyngitis, and cervical adenitis)
- Psychogenic pain (globus hystericus)
- Vitamin deficiency (A, B complex, C)
- Dehydration
Treatment
General Measures
Treatment is largely supportive for most viral causes of pharyngitis, including pain control and hydration.
Medication
First Line
- Penicillin-resistant GAS has never been documented. Apparent treatment failure (recurrent episode of acute pharyngitis with positive lab tests for GAS) most likely indicates repeat intercurrent viral infection in GAS carrier.
- Oral penicillin V
- Children: 400,000 U (250 mg) b.i.d. or t.i.d. for 10 days
- Adolescents/adults: 800,000 U (500 mg) b.i.d. for 10 days or 400,000 U (250 mg) 3 " 4 times per day for 10 days
- Amoxicillin: 50 mg/kg (max dose 1 g) daily divided b.i.d. for 10 days
- Once-daily dosing may increase adherence.
- Intramuscular (IM) penicillin G benzathine: ensures compliance, useful in outbreaks
- Children (>1 month and <27 kg): 600,000 U IM 1
- Children (>27 kg) and adults: 1,200,000 U IM 1
- Procaine penicillin combinations are less painful.
Second Line
- A 10-day course of a 1st-generation oral cephalosporin is indicated for most penicillin-allergic patients. However, 5 " 10% of penicillin-allergic patients may also be allergic to cephalosporins, so patients with a type I hypersensitivity to penicillin should not be given a cephalosporin.
- Oral clindamycin 20 mg/kg/24 h (max 1.8 g/24 h) divided t.i.d. may be given to patients with type I hypersensitivity to penicillin.
- Oral azithromycin, clarithromycin, or erythromycin are also acceptable alternatives in penicillin-allergic patients, although cases of ARF have been reported after treatment with these drugs.
- Azithromycin 12 mg/kg (max 500 mg) daily for 5 days
- Clarithromycin, 15 mg/kg/24 h divided q12h for 10 days or 500 mg extended-release tablets given once a day for 5 days (studied in adolescents ≥12 years of age)
- Erythromycin ethylsuccinate, 40 " 50 mg/kg/24 h in 2 " 4 divided doses. Resistance is rare in the United States (<5% of isolates).
- Tetracyclines and sulfonamides should not be used due to high rates of resistance.
- In patients with N. gonorrhoeae infection
- 250 mg ceftriaxone IM (>45 kg); 125 mg ceftriaxone IM (<45 kg)
- Coinfection with C. trachomatis is unusual in pharyngitis caused by N. gonorrhoeae; however, treatment is recommended: azithromycin 1 g PO in adolescents. In younger children, should confirm infection
- In patients with EBV
- Antibiotics should not be given; in particular, if amoxicillin or ampicillin is given, a high proportion of patients will develop a nonallergic rash.
- Short-course corticosteroids may be beneficial but can also have significant adverse effects; should only be used in patients with marked tonsillar inflammation and impending airway obstruction. Usual prednisone dose is 1 mg/kg/24 h for 7 days with subsequent tapering.
Surgery/Other Procedures
Tonsillectomy for recurrent pharyngitis is not recommended but may be considered in the rare patient who has frequent symptomatic episodes of pharyngitis in whom no alternative explanation to GAS pharyngitis is found (e.g., recurrent viral infections in a GAS carrier). Benefit is relatively short-lived.
Ongoing Care
Patient Monitoring
- Most cases of pharyngitis are self-limited; however, patients are at risk for dehydration if PO intake is limited by pain.
- Caregivers should be cautioned to monitor fluid intake and urine output and to return for reassessment if oral intake and/or urine output drops significantly.
Complications
- Streptococcal pharyngitis
- Suppurative complications include peritonsillar abscess, cervical lymphadenitis, and mastoiditis.
- Most significant nonsuppurative complication is ARF. This can be prevented if adequate antibiotic treatment is provided within 10 days.
- Another nonsuppurative complication is poststreptococcal glomerulonephritis.
- Lemierre syndrome: spread of F. necrophorum from peritonsillar abscess caused by GAS to jugular vein causing thrombophlebitis, bacteremia, and thromboembolism
- Pediatric autoimmune neuropsychiatric disorder associated with streptococcal infection (PANDAS): controversial association that has not been demonstrated in prospective studies
Additional Reading
- Leckman JF, King RA, Gilbert DL, et al. Streptococcal upper respiratory tract infections and exacerbations of tic and obsessive-compulsive symptoms: a prospective longitudinal study. J Am Acad Child Adolesc Psychiatry. 2011;50(2):108 " 118. [View Abstract]
- Logan LK, McAuley JB, Shulman ST. Macrolide treatment failure in streptococcal pharyngitis resulting in acute rheumatic fever. Pediatrics. 2012;129(3):e798 " e802. [View Abstract]
- Shulman ST, Bisno AL, Clegg HW, et al. Clinical practice guideline for the diagnosis and management of group A streptococcal pharyngitis: 2012 update by the Infectious Diseases Society of America. Clin Infect Dis. 2012;55(10):e86 " e102. [View Abstract]
Codes
ICD09
- 462 Acute pharyngitis
- 034.0 Streptococcal sore throat
- 074.0 Herpangina
- 054.79 Herpes simplex with other specified complications
ICD10
- J02.9 Acute pharyngitis, unspecified
- J02.0 Streptococcal pharyngitis
- B08.5 Enteroviral vesicular pharyngitis
- B00.2 Herpesviral gingivostomatitis and pharyngotonsillitis
- J02.8 Acute pharyngitis due to other specified organisms
SNOMED
- 405737000 Pharyngitis (disorder)
- 43878008 Streptococcal sore throat (disorder)
- 186659004 Herpangina
- 232399005 Acute herpes simplex pharyngitis (disorder)
- 78430008 Adenoviral pharyngitis (disorder)
FAQ
- Q: Is there any benefit to starting therapy while waiting for culture results?
- A: Immediate therapy probably shortens the symptomatic period. However, waiting for culture is appropriate because the goal of treatment is to minimize progression to ARF, and treatment within 10 days of onset of symptoms is effective.
- Q: Should all patients with sore throat be swabbed for RADT and/or strep culture?
- A: No. Most cases of sore throat are not due to GAS. However, clinical exam alone is insufficient to diagnose strep throat. Patients with symptoms that highly suggest a viral etiology (rhinorrhea, congestion, cough, conjunctivitis) should not be tested for GAS, as a positive result would most likely indicate carrier status rather than GAS pharyngitis.
- Q: Should contacts of patients with documented GAS pharyngitis be tested for GAS?
- A: Contacts who have recent or current clinical symptoms of GAS infection should undergo appropriate testing. However, carrier rates of contacts are quite high, up to 50% for siblings and 20% for other contacts, so routine testing of asymptomatic contacts is usually not indicated except during outbreaks or when contacts are at increased risk of developing sequelae of infection.