Pharyngitis (sore throat) is an inflammation of the pharynx or throat – the area between the tonsils and the larynx (voice box). A sore throat is characterised by redness, swelling and pain in this area, which can make swallowing or speech difficult.
The pharynx is connected to the mouth, nose, oesophagus, larynx and ears. It is also close to the tonsils (at the back of the pharynx) and the adenoids (higher up in the nasal portion of the pharynx). Frequently pharyngitis also involves these other structures.
A sore throat is usually the first symptom of a mild illness such as a cold or the flu. However, it can also be an indication of a more serious condition, such as strep throat or scarlet fever.
Sore throat can be caused by viruses or bacteria.
Viruses cause most sore throats:
- Most commonly, the viruses that cause the common cold are responsible for viral pharyngitis.
- Infectious mononucleosis (mono) is another very common viral infection that can cause a severe sore throat and inflammation of the tonsils.
- In young children, the condition is usually mild, and can be mistaken for a common cold or flu.
- When mono occurs after childhood, however, the disease can be extremely serious. It affects the liver and spleen, and may lead to jaundice.
- Other viral infections that can result in pharyngitis include influenza (flu), measles, chickenpox and herpes.
Bacteria can also cause a sore throat:
- The most common bacterial cause of a sore throat is the streptococcus bacterium, which causes the serious condition strep throat.
- Five to 10% of adult sore throats are caused by streptococcus infection.
- Strep infection is involved in 15 to 40% of sore throats in children.
- Strep throat should be diagnosed as quickly as possible because of the serious complications that can develop if left untreated. These include rheumatic fever, which can damage the heart, and acute nephritis, which can damage the kidneys; both can be fatal.
- The onset of strep throat is characterised by sudden high fever and a severe sore throat.
- The bacterium responsible for scarlet fever, a strep-related illness, can also cause pharyngitis.
- Micro-organisms such as the yeast candida can produce a sore throat.
- A sore throat can also result from exposure through oral sex to the bacterium that causes gonorrhoea.
- Pharyngitis that lasts for a long time (chronic pharyngitis) can be due to a respiratory, sinus, or mouth infection that spreads to the throat.
- Smoking cigarettes, consuming excessive alcohol, breathing in chemical fumes or air pollution, or swallowing substances that irritate or damage the lining of the throat can also cause pharyngitis.
- Breathing through the mouth can make the throat dry and sore. Living in a dry or dusty environment and breathing in very dry air can cause rawness and pain.
- Overuse of the voice can result in throat pain and hoarseness.
- Sinus drainage can cause pharyngitis.
- Rarely, a sore throat may be caused by a cancerous growth in the throat or mouth.
Inflammation of the pharynx causes it to redden and swell. The condition is characterised by a raw, scratchy or burning sensation in the back of the throat, and pain, especially when swallowing.
Other symptoms may include:
- Tenderness or swollen glands at the front of the neck
- Sneezing and coughing
- Runny nose
- Mild fever
- General fatigue
- Painful breathing and speaking
- Pus in the throat
A sore throat is an extremely common complaint. It is particularly prevalent during the colder months of the year, when respiratory diseases are most widespread.
Typically, a sore throat should disappear within a week. A sore throat that lasts longer than two weeks can be a sign of a serious illness, such as throat cancer or Aids.
People who suffer from allergies, persistent coughs or chronic sinusitis are particularly prone to sore throats.
When to see a doctor
You should seek medical attention if:
- You quickly develop a fever and sore throat simultaneously; these are the classic symptoms of strep throat, which should be treated as soon as possible. Other signs of strep throat are a sore throat without other cold symptoms, swollen "glands" (lymph nodes in the neck), and white patches on the back of the throat. If you have a sore throat and have been in contact with someone with strep throat, you should also have a strep test.
- Your sore throat persists for more than a week; if this is accompanied by postnasal drip, it may indicate allergies. Any sore throat that lasts for more than two weeks can be a symptom of a serious illness, such as throat cancer or Aids. Hoarseness that lasts longer than two weeks can also be a sign of throat or oral cancer.
- You find it difficult to swallow liquids (although some pain with swallowing can be expected with any sore throat)
- You have flu-like symptoms that don't improve after a few days; this may indicate infectious mononucleosis.
- Your sore throat is accompanied by drooling, or you have trouble swallowing or breathing. These symptoms may be the result of one of two rare conditions: an inflamed epiglottis, or an abscess in the throat.
A health professional should examine your throat and ask you to describe your symptoms. From this examination alone, it may be difficult to determine whether your sore throat is the result of a viral or a bacterial infection.
To diagnose strep throat, your doctor may do a so-called rapid strep test. This test takes only about 15 to 20 minutes, and can usually be done in the office. If the result is not strongly negative and you have strep symptoms, your doctor may then also take a more traditional throat culture, which takes longer to be analysed.
Taking a throat culture is a painless procedure; it involves taking a sample of throat mucus with a swab. If your doctor’s office is not suitably equipped, the sample may have to be sent to an outside laboratory for analysis.
Because infectious mononucleosis has such a wide range of symptoms, it can be difficult for a doctor to immediately diagnose it. After doing a physical exam, the doctor may take a blood sample to check for the presence of abnormal white blood cells or antibodies to mono.
You should also be examined for symptoms of any other conditions, such as sinus, chest, or ear infections. If you have such symptoms, or if the throat pain persists, additional tests may be necessary.
Usually no specific treatment is required if you have viral pharyngitis (such as mono), which usually clears up within a week.
Bacterial infections such as strep throat can be effectively treated with antibiotics. Antibiotics do not help with viral infections.
For chronic pharyngitis (persistent pain due to a respiratory, sinus, or mouth infection spreading to the throat), your doctor should treat the primary source of infection.
Most sore throats will go away by themselves after a few days and can be effectively treated at home.
To relieve the pain and discomfort of a sore throat, you could try the following:
- Get a lot of rest.
- Drink plenty of fluids.
- Gargle with warm salt water or some other home-made gargle to wash away mucus and irritants.
- Avoid smoking cigarettes.
- Eat largely soft foods for a couple of days to avoid irritating your throat.
- Suck non-prescription lozenges containing a mild anaesthetic. Zinc lozenges can relieve sore throats and other cold symptoms. Mildly anaesthetic sprays and mouthwashes are also available over the counter.
- If mouth breathing or dry air causes your sore throat, try using a humidifier in your home.
- If your nose is blocked, use a nasal spray to prevent mouth breathing. (Caution: using these products for more than a couple of days may result in dependency. If you have heart disease or high blood pressure, check with a doctor before using any decongestant products.)
- Apply a warm heating pad, compress or salt plaster to your throat.
- Try steam inhalations.
- When necessary, use mild pain relievers such as aspirin, ibuprofen or acetaminophen. (Caution: do not give aspirin to a child or young adult. Aspirin has been linked to Reye's syndrome, a rare but serious condition.)
- If your sore throat is so severe that it makes breathing or eating difficult, your doctor may give you prednisone, a steroid drug.
- For acute bacterial pharyngitis (such as strep throat), your doctor will probably prescribe antibiotics:
- Penicillin or some other antibiotic such as erythromycin is commonly prescribed for seven to 10 days.
- You will feel better after taking antibiotics for 24 hours – but it is important to complete the full course of antibiotics, even after symptoms disappear.
- Antibiotics may not always shorten the course of the disease, but they will kill the bacteria and cut down the risk of serious strep complications.
- If you are prone to sore throats, try changing your toothbrush every month – the bristles can harbour bacteria. Also throw away your old toothbrush after recovery from a sore throat so as not to reinfect yourself.
- Try not to share eating and drinking utensils with other people.
- When you use public telephones or water faucets, try to avoid touching them with your nose or mouth.
- Do not have close contact with someone who has a sore throat.
- If you live in a polluted environment, try to stay indoors as much as possible on days when the pollution is very bad.
- Don't consume large amounts of alcohol.
- Avoid areas where there is a lot of cigarette smoke.
- If the air is very dry, try humidifying your home.
- Build up your body's natural defences: reduce stress levels and get plenty of rest. This can help you to avoid infections such as strep throat.
(Reviewed by Dr D. Wagenfeld)