Pharyngitis (far-in-jī' tis) is a painful inflammation of the pharynx, and is colloquially referred to as a sore throat. Infection of the tonsils, tonsillitis may occur simultaneously.

The major cause is infection, of which 90% are viral, the remainder caused by bacterial infection and rarely oral thrush (fungal candidiasis e.g. in babies). Some cases of pharyngitis are caused by irritation from agents such as pollutants or chemical substances.

Causes

Viral sore throats

These comprise about 90% of all infectious cases and can be a feature of many different types of viral infections.

• 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 is very painful.
• Orthomyxoviridae which cause influenza - present with rapid onset high temperature, headache and generalised 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

Bacterial sore throats

Group A Streptococcal

The most common bacterial agent is streptococcus. Unlike adenovirus, there tends to be greater generalised symptoms and more signs to find. Typically enlarged and tender lymph glands, with bright red inflamed and swollen throat, the patient may have a high temperature, headache, and aching muscles (myalgia) and joints (arthralgia).

Some immune-system meditated complications may occur:

• Scarlet fever with its vivid rash, although the milder disease seen after the 1950's suggests that the bacteria may have mutated to less virulent illness and some doctors now call this scarlatina (literally a 'little scarlet fever')
• Historically the most important complication was of the generalised inflammatory disorder of rheumatic fever which could later result in Rheumatic heart disease affecting the valves of the heart. Antibiotics may reduce the incidence of this complication to under a third.^[1]However the incidence of rheumatic fever in developed-regions of the world remains low even though the use of antibiotics has been declining.^[2][3]This may be a result of a change in the prevalence of various strains of bacteria. In underdeveloped regions, untreated streptococcal infection can still give rise to rheumatic heart disease and may be due to environmental factors, or reflect a genetic predisposition of the patient to the disease.
• Post-streptococcal glomerulonephritis is an inflammation of the kidney. It is disputed whether antibiotics might reduce^[4] the small risk of this or not.^[1]
• Very rarely there may occur a secondary infection behind the tonsils which may cause a life-threatening septicaemia (Lemierre's syndrome)

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.

Treatment

Without treatment most pharyngitis will settle spontaneously within a few days. Hence the main focus of treatment is symptomatic. Specific treatment of pharyngitis will vary according to the cause, with the one important one being adequate treatment of streptococcal infections in children susceptible to rheumatic fever, such as Australian aboriginals.

• Antibiotics are only helpful when a bacterial infection is the cause of the sore throat. For viral sore throats, antibiotics have been shown to only affect the degree of pain by day 4 and shorten the average natural duration by 16 hours overall (14 people need be treated for a week to reduce the duration by one day).^[1]
• Iodine compounds sold as Betadine or TCP can be gargled to shorten the duration of the infection.^{citation needed]} These compounds are effective anti-viral agents.

Symptomatic

Twenty-two non-antibiotic managements for sore throat have been studied in controlled trials.^[5]Analgesics are among the most effective, but there are many simple measures that can also be used.

• Analgesics such as NSAIDs can help reduce the pain associated with a sore throat.
• Throat lozenges (cough medicine) are often used for short-term pain relief.
• Gargling with warm salty water is a popular household remedy, although there is only anecdotal evidence this gives anything other than temporary relief and likewise for the use of aspirin gargles. Gargling with salty water can help clear up mucus.
• Honey has long been used for treating sore throats due to its antiseptic properties.
• Warm tea (true or herbal) or soup can help temporarily alleviate the pain of a sore throat.
• Cold beverages and popsicles numb the nerves of the throat somewhat, alleviating the pain for a brief time.
• Mouthwash (when gargled) reduces the pain but only for a brief time.
• There have been some studies that show ingesting a solution high in protein can have a profound relieving effect on sore throats, particularly if they are allergy related.^{citation needed]}
• Drinking heavy amounts of liquid reduces the pain for a short time.
• Peppermint candy might help with some cases as well as other hard candies. It will reduce the pain for a short time.
• Raw juice of papaya leaves may help to recover sore throat.^{citation needed]}
• Yogurt has been shown to help alleviate the pain temporarily by coating the affected area.^{citation needed]}
• Raw juice of lemon or lime may help destroy bacteria in bacteria-related throat infections but the high acid content may irritate the affected throat tissues more.
• Alcohol has a mild analgesic and antiseptic effect, but may also weaken the immune system.