STREP THROAT - a patient's guide
- Strep throat is an infection with group A streptococcus bacteria which causes a sore throat.
- The infection can also cause a fever, swollen lymph glands, and a rash also known as scarlet fever in rare cases.
- The infection is a trigger in some cases of rheumatic fever and the kidney disorder glomerulonephritis. The risk of rheumatic fever is extremely low in most western populations. Overcrowding and poverty seems to be associated with an increased risk of this complication.
- Antibiotics have been used to treat strep throat in the past but there is now controversy over the routine use of antibiotics.Most doctors will balance the risk of rheumatic fever in a particular patient against the risks associated with antibiotic usage.
- If antibiotics are prescribed they must be taken for at least 10 days to destroy the streptococci bacteria.
What is it?
Strep throat is an infection with the bacteria group A streptococci, and is the most common bacterial infection causing a sore throat.
An estimated 10 percent of people with sore throats will have strep throat. The other 90 percent will usually have a viral infection.
It is common in the winter months and in crowded living conditions. It most commonly affects children and young people aged five to 15.
It is spread through coughing and sneezing and sharing cups and utensils, and has an incubation period of between two days to one week. If someone in the family has strep throat, it is estimated that one in four people in the house will also get infected.
Some people are carriers of group A streptococcus. These people have the bacteria in their throats all the time without becoming ill (asymptomatic) and can cause illness in others by spreading the bacteria. It is believed up to 15 percent of school children are asymptomatic carriers.
Group A streptococci can also cause throat abscesses, ear infections, sinusitis, and skin infections such as impetigo.
What are the symptoms of strep throat?
The symptoms of strep throat vary according to the patient's age. Most people will have a sore throat with swollen tonsils and white or yellow flecks of pus at the back of the throat.
Babies may have a coloured discharge from their nose, a fever, and may have difficulty feeding.
Toddlers may complain of a sore throat (or neck), have swollen glands in the neck and behind the jaw, have difficulty swallowing and refuse food.
Older children usually have a high fever (over 38,5 degrees C) and severe difficulty swallowing, with pus covering their tonsils.
A throat swab is normally taken and sent to a laboratory to confirm infection with streptococcus.
In most cases the fever breaks within three to five days and the sore throat gets better following this.
Diagnosing a Strep Throat.
Research has shown that it is difficult to confidently tell strep throat from more common viral infections.
The presence of a runny nose may be a pointer to a viral infection.A higher fever and predominantly sore throat might make strep infection more likely.
Throat swabs can help in diagnosis, although does not 100% confirm that the sore throat is being caused by the strep infection,as a proportion of healthy people(10 to 15 percent) may carry strep in their throats.
An antibody tests on the blood ,showing a rise over 2 weeks can confirm strep infection,but this is not practical in the management of most strep sore throats.
What are the possible consequences of strep throat?
A rough red rash can appear with strep throat in rare cases. This condition is known as scarlet fever but this is no more dangerous than strep throat without a rash.
Strep throat can lead to acute rheumatic fever which can cause heart valve problems and joint pain.The relationship of strep infection to rheumatic fever is complex and at least half of all cases of rheumatic fever do not have preceding sore throat,so clearly other factors are also involved in the cause of rheumatic fever.
Acute rheumatic fever is very uncommon in children under 4 years old.
The risk of rheumatic fever has been declining in many countries,although certain groups within the population may be at higher risk and thus influence how doctors diagnose and treat sore throats within these groups.
Examples of risk of rheumatic fever ;
New-Zealand children of European descent; 2:100000/year
New-Zealand Maori and Pacific Islanders; 40-70/100000/year.
Rarely the kidneys may be affected although this is more common after strep skin infection.
Some children or adults can have a spate of strep throat infections. This may be due to the patient being a carrier of strep, there is a carrier in the family, or that the initial infection was never eradicated.
In rare cases strep throat can lead to pneumonia, usually after the patient has had the flu, whooping cough (pertussis) or chicken pox.
What can be done?
In most cases strep throat will resolve by itself, without the need for drug treatment.
Antibiotics have traditionally been used to cure strep throat and they are still recommended in the US. However, there is now controversy in Britain and in other countries about using antibiotics for a sore throat.
A Cochrane review of the medical literature has found that 90 percent of patients with a sore throat feel better within one week, regardless of whether they are treated with antibiotics or not.
Studies have found that a small number of people treated with antibiotics feel better after three days compared to those not taking medicine, but this is only a marginal benefit.
Studies from the 1950s show that the use of antibiotics does reduce the rate of acute rheumatic fever following strep throat but this illness is rare.
The decision to take antibiotics should be weighed against the potential side effects of the drugs including diarrhoea, skin rashes, thrush (candida), and the rare occurrence of anaphylaxis and the risk of bacterial resistance to antibiotics.
There is also concern that the infection can recur when strep throat has been treated with antibiotics.
Antibiotics may be required for people who are seriously ill. They are also generally advised in parts of the world where rheumatic fever is common. They may also be recommended if there is also an accompanying ear infection with a sore throat.
If antibiotics are prescribed they must be taken for at least 10 days in order to destroy streptococci bacteria. Commonly prescribed antibiotics include amoxicillin, penicillin, and erythromycin.
Other methods to relieve strep throat include sucking throat lozenges or gargling with salt water if the patient is old enough. Paracetamol is a good pain reliever for children. Throat sprays can be used in adults.
Give plenty of water to drink, soft drinks, ice blocks, milkshakes, and soft foods such as cheese, ice cream, jelly, soup, and mashed vegetables.
Your doctor will be able to advise on the best treatment for a sore throat. Immediate medical attention is required if the patient can hardly swallow, is drooling, or having trouble breathing.
Most sore throats do not require medical attention. However, if a child has a sore throat associated with severe symptoms or fever, medical advice should be sought from your doctor.
If a sore throat does not resolve in a week or so, or if you are concerned about other associated symptoms (e.g. earache or headache) it is also wise to seek advice.