Pharyngitis

Pharyngitis
Inflamed oropharynx: swollen and red.
Classification and external resources
Pronunciation	/færᵻnˈdʒaɪtᵻs/
Specialty	Infectious disease
ICD-10	J02, J31.2
ICD-9-CM	462, 472.1
DiseasesDB	24580
MedlinePlus	000655
eMedicine	emerg/419
MeSH	D010612

Pharyngitis is the inflammation of the pharynx, a region in the back of the throat.^[1] In most cases it is painful, and it is the most common cause of a sore throat.^[2] Like many types of inflammation, pharyngitis can be chronic (long-lasting) or acute (quickly developing and temporary). Pharyngitis can result in very large tonsils, which cause trouble swallowing and breathing. Pharyngitis can be accompanied by a cough or fever, especially if caused by a systemic infection.

Most acute cases are caused by viral infections (40–80%), with the remainder caused by bacterial infections, fungal infections, or irritants such as pollutants or chemical substances.^[2][3] Treatment of viral causes is mainly symptomatic, but bacterial or fungal causes may be treated with antibiotics and anti-fungal medicines respectively.

On the average, children experience sore throats about five times a year, adults twice a year.^[4] The word comes from the Greek word pharynx meaning "throat" and the suffix -itis meaning "inflammation."

Classification

Pharyngitis is a type of inflammation, most commonly caused by an upper respiratory tract infection. It may be classified as acute or chronic. An acute pharyngitis may be catarrhal, purulent or ulcerative, depending on the virulence of the causative agent and the immune capacity of the affected individual. Chronic pharyngitis is the most common otolaringologic disease and may be catarrhal, hypertrophic or atrophic.

If the inflammation includes tonsillitis, it may be called pharyngotonsillitis.^[5] Another sub classification is nasopharyngitis (the common cold).^[6]

Cause

The majority of cases are due to an infectious organism acquired from close contact with an infected individual.

Infectious

Viral

These comprise about 40–80% of all infectious cases and can be a feature of many different types of viral infections.^[2][3]

• Adenovirus – the most common of the viral causes. Typically the degree of neck lymph node enlargement is modest and the throat often does not appear red, although it is painful.
• Orthomyxoviridae which cause influenza – present with rapid onset high temperature, headache and generalized ache. A sore throat may be associated.
• Infectious mononucleosis ("glandular fever") caused by the Epstein–Barr virus. This may cause significant lymph gland swelling and an exudative tonsillitis with marked redness and swelling of the throat. The heterophile test can be used if this is suspected.
• Herpes simplex virus can cause multiple mouth ulcers.
• Measles
• Common cold: rhinovirus, coronavirus, respiratory syncytial virus, parainfluenza virus can cause infection of the throat, ear, and lungs causing standard cold-like symptoms and often pain.

Bacterial

A number of different bacteria can infect the human throat. The most common is Group A streptococcus, but others include Streptococcus pneumoniae, Haemophilus influenzae, Bordetella pertussis, Bacillus anthracis, Corynebacterium diphtheriae, Neisseria gonorrhoeae, Chlamydophila pneumoniae, and Mycoplasma pneumoniae.^[7]

Streptococcal pharyngitis

A case of strep throat

Streptococcal pharyngitis or strep throat is caused by group A beta-hemolytic streptococcus (GAS).^[8] It is the most common bacterial cause of cases of pharyngitis (15–30%).^[7] Common symptoms include fever, sore throat, and large lymph nodes. It is a contagious infection, spread by close contact with an infected individual. A definitive diagnosis is made based on the results of a throat culture. Antibiotics are useful to both prevent complications and speed recovery.^[9]

Fusobacterium necrophorum

Fusobacterium necrophorum is a normal inhabitant of the oropharyngeal flora and can occasionally create a peritonsillar abscess. In 1 out of 400 untreated cases, Lemierre's syndrome occurs.^[10]

Diphtheria

Diphtheria is a potentially life-threatening upper respiratory infection caused by Corynebacterium diphtheriae which has been largely eradicated in developed nations since the introduction of childhood vaccination programs, but is still reported in the Third World and increasingly in some areas in Eastern Europe. Antibiotics are effective in the early stages, but recovery is generally slow.

Others

A few other causes are rare, but possibly fatal, and include parapharyngeal space infections: peritonsillar abscess ("quinsy"), submandibular space infection (Ludwig's angina), and epiglottitis.^[11][12][13]

Fungal

Some cases of pharyngitis are caused by fungal infection such as Candida albicans causing oral thrush.

Non-infectious

Pharyngitis may also be caused by mechanical, chemical or thermal irritation, for example cold air or acid reflux. Some medications may produce pharyngitis such as pramipexole and antipsychotics.^[14][15]

Diagnostic approach

Modified Centor score

Points	Probability of Strep	Management
1 or less	<10%	No antibiotic or culture needed
2	11–17%	Antibiotic based on culture or RADT
3	28–35%
4 or 5	52%	Empiric antibiotics

It is hard to differentiate a viral and a bacterial cause of a sore throat based on symptoms alone.^[16] Thus often a throat swab is done to rule out a bacterial cause.^[17]

The modified Centor criteria may be used to determine the management of people with pharyngitis. Based on 5 clinical criteria, it indicates the probability of a streptococcal infection.^[9]

One point is given for each of the criteria:^[9]

• Absence of a cough
• Swollen and tender cervical lymph nodes
• Temperature >38.0 °C (100.4 °F)
• Tonsillar exudate or swelling
• Age less than 15 (a point is subtracted if age >44)

The McIsaac criteria adds to the Centor:^[18]

• Age less than 15: add one point
• Age greater than 45: subtract one point

The Infectious Disease Society of America however recommends against empirical treatment and considers antibiotics only appropriate following positive testing.^[16] Testing is not needed in children under three as both group A strep and rheumatic fever are rare, except if they have a sibling with the disease.^[16]

Management

The majority of time treatment is symptomatic. Specific treatments are effective for bacterial, fungal, and herpes simplex infections.

Medications

• Analgesics such as NSAIDs and acetaminophen (Paracetamol) can help reduce the pain associated with a sore throat. Aspirin may be used in adults but is not recommended in children due to the risk of Reye syndrome.^[19]
• Steroids (such as dexamethasone) have been found to be useful for severe pharyngitis.^[20][21]
• Viscous lidocaine relieves pain by numbing the mucus membranes.^[22]
• Antibiotics are useful if a bacterial infection is the cause of the sore throat. For viral infections, antibiotics have no effect.^[23]
• Oral analgesic solutions, the active ingredient usually being phenol, but also less commonly benzocaine, cetylpyridinium chloride and/or menthol. Chloraseptic and Cēpacol are two examples of brands of these kinds of analgesics.

Alternative

Alternative medicines are promoted and used for the treatment of sore throats.^[24] However, they are poorly supported by evidence.^[24]

Epidemiology

Acute pharyngitis is the most common cause of a sore throat and, together with cough, it is diagnosed in more than 1.9 million people a year in the United States.^[2]

References

1. "Pharyngitis". ClinicalKey.
2. Marx, John (2010). Rosen's emergency medicine: concepts and clinical practice (7th ed.). Philadelphia, Pennsylvania: Mosby/Elsevier. Chapter 30. ISBN 978-0-323-05472-0.
3. Acerra JR. "Pharyngitis". eMedicine. Retrieved 28 April 2010.
4. Tamparo, Carol (2011). Fifth Edition: Diseases of the Human Body. Philadelphia, PA: F.A. Davis Company. p. 356. ISBN 978-0-8036-2505-1.
5. Rafei K, Lichenstein R (2006). "Airway Infectious Disease Emergencies". Pediatric Clinics of North America 53 (2): 215–242. doi:10.1016/j.pcl.2005.10.001. PMID 16574523.
6. "www.nlm.nih.gov".
7. Bisno AL (January 2001). "Acute pharyngitis". N Engl J Med 344 (3): 205–11. doi:10.1056/NEJM200101183440308. PMID 11172144.
8. Baltimore RS (February 2010). "Re-evaluation of antibiotic treatment of streptococcal pharyngitis". Curr. Opin. Pediatr. 22 (1): 77–82. doi:10.1097/MOP.0b013e32833502e7. PMID 19996970.
9. Choby BA (March 2009). "Diagnosis and treatment of streptococcal pharyngitis". Am Fam Physician 79 (5): 383–90. PMID 19275067.
10. Centor RM (2009-12-01). "Expand the pharyngitis paradigm for adolescents and young adults". Ann Intern Med 151 (11): 812–5. doi:10.1059/0003-4819-151-11-200912010-00011. PMID 19949147.
11. "UpToDate Inc.". (registration required)
12. Reynolds SC, Chow AW (Sep–Oct 2009). "Severe soft tissue infections of the head and neck: a primer for critical care physicians". Lung 187 (5): 271–9. doi:10.1007/s00408-009-9153-7. PMID 19653038.
13. Bansal A, Miskoff J, Lis RJ (January 2003). "Otolaryngologic critical care". Crit Care Clin 19 (1): 55–72. doi:10.1016/S0749-0704(02)00062-3. PMID 12688577.
14. "Mirapex product insert" (PDF). Boehringer Ingelheim. 2009. Retrieved 2010-06-30.
15. "Mosby's Medical Dictionary, 8th edition". Elsevier. 2009. Retrieved 2010-06-30.
16. Shulman ST, Bisno AL, Clegg HW, Gerber MA, Kaplan EL, Lee G, Martin JM, Van Beneden C (Sep 9, 2012). "Clinical Practice Guideline for the Diagnosis and Management of Group A Streptococcal Pharyngitis: 2012 Update by the Infectious Diseases Society of America.". Clinical Infectious Diseases 55 (10): e86–102. doi:10.1093/cid/cis629. PMID 22965026.
17. Del Mar C (1992). "Managing sore throat: a literature review. I. Making the diagnosis". Med J Aust 156 (8): 572–5. PMID 1565052.
18. Fine AM, Nizet V, Mandl KD (2012). "Large-Scale Validation of the Centor and McIsaac Scores to Predict Group A Streptococcal Pharyngitis.". Arch Intern Med 172. doi:10.1001/archinternmed.2012.950. PMID 22566485.
19. Baltimore RS (February 2010). "Re-evaluation of antibiotic treatment of streptococcal pharyngitis". Current Opinion in Pediatrics 22 (Curr. Opin. Pediatr. 22 (1)): 77–82. doi:10.1097/MOP.0b013e32833502e7. PMID 19996970.
20. Hayward G, Thompson M, Heneghan C, Perera R, Del Mar C, Glasziou P (2009). "Corticosteroids for pain relief in sore throat: systematic review and meta-analysis". BMJ 339: b2976. doi:10.1136/bmj.b2976. PMC 2722696. PMID 19661138.
21. "Do steroids reduce symptoms in acute pharyngitis?". BestBets.org. Retrieved 2009-01-14.
22. "LIDOCAINE VISCOUS (Xylocaine Viscous) side effects, medical uses, and drug interactions.".
23. Del Mar CB, Glasziou PP, Spinks AB (2004). Del Mar, Chris, ed. "Antibiotics for sore throat". Cochrane Database Syst Rev (2): CD000023. doi:10.1002/14651858.CD000023.pub2. PMID 15106140. - Meta-analysis of published research
24. "Sore throat: Self-care". Mayo Clinic. Retrieved 2007-09-17.