Every year there is an estimated 12 million cases of sore throat reported to health care providers across the United States. The most common cause of sore throat is Group A Streptococcus, commonly referred to as strep throat. This type of throat infection (pharyngitis) is mainly seen during winter and early spring, and tends to be more common among children. However, it can occur at anytime of the year and also affect adults.
Sore Thoat vs Strep Throat
A sore throat is a symptom where there is discomfort or pain in the throat. The most common cause is a throat infection (acute pharyngitis). However, there can be other non-infectious causes of a sore throat, such as reflux pharyngitis where stomach acid and enzymes irritates the throat. Most of the time acute pharyngitis is due to a bacterial infection. The most common bacteria is Streptococcus pyogenes, which belongs to Group A Streptococcus (GAS).
Read more on strep throat.
Therefore a sore throat refers to a symptom while strep throat refers to a bacterial infection of the throat caused by Streptococcus pyogenes. This bacterium is highly virulent meaning that it has a tendency to cause disease even in a healthy person. Although it can cause skin, lung and ear infections, Streptococcus pyogenes most frequently causes throat infections. In fact up to 30% of acute pharyngitis cases are due to Streptococcus pyogenes. It is also responsible for other conditions like rheumatic fever and scarlet fever.
Is strep throat the same as scarlet fever or rheumatic fever?
Strep throat, scarlet fever and rheumatic fever are separate conditions with many similarities. Firstly all of these conditions are caused by Group A Streptococci. Strep throat is an infection of the throat with these bacteria. Scarlet fever and rheumatic fever are inflammatory conditions also caused by these bacteria.
Scarlet fever arises when the toxin produced by this bacteria is distributed throughout the body where it triggers inflammation. Rheumatic fever is another inflammatory condition caused by Group A Streptococci due to autoimmune reaction and the valves of the heart are most commonly affected.
How to Spot Strep Throat
Without a throat culture, it can sometimes be difficult to differentiate strep throat from other bacterial infections of the throat and even viral throat infections solely on the signs and symptoms. The skin rash that can occur in some susceptible individuals may be a defining sign when considered with the other symptoms.
The incubation period is between 2 to 4 days. This means that symptoms arise after 2 to 4 days from the time of infection. Always consult with a doctor if a sore throat is severe and not easing within 48 hours of using the appropriate treatment, like antibiotics.
Throat pain is the most common symptom and initially starts off as a slight discomfort in the throat. It arises suddenly. It is accompanied by painful swallowing (odynophagia). Similarly the throat pain may be exacerbated by talking. Often a person with strep throat will not want to eat due to the discomfort and pain. Even swallowing water elicits pain although solids are worse.
The tonsils are swollen and red due to the inflammation. This is the tissue situated at the back of the throat on either side. Sometimes there may be white patches on the inflamed tonsils. Streak of pus over the tonsils may also be visible. In addition there may be tiny red spots on the palate (roof of the mouth) and a beefy red appearance of the uvula. Usually the extent of the redness and swelling of the tonsils correlates with the severity of throat pain.
The lymph nodes on the neck are usually enlarged in strep throat. This is a sign of heightened immune activity and can persist even after the infection resolves and other symptoms subside. Enlarged lymph nodes, known as lymphadenopathy, is helpful in differentiating between infectious and non-infectious causes of a sore throat. Most of the time the enlargement is an indication of an infection, although some infections do not cause lymph node swelling.
There is usually a high fever present with strep throat, with the temperature being higher than 101°F (38.3°C). However, the presentation in infants may be misleading as there is a low-grade fever. Typically the fever persists for more than 48 hours. In contrast certain viral upper respiratory tract infections that may cause a sore throat do not always cause a fever.
In some sensitive individuals, a skin rash may develop. It typically appears as tiny red pimples with the redness of the affected skin. When this rash does appear, it usually arises within 1 to 2 days of the other symptoms starting and resolves within 3 to 4 days. The rash starts on the neck and spreads downwards to the trunk and arms. This rash is known as a scarlitiniform rash.
- Body aches
- Nausea with/without vomiting (more likely to occur in young children)
Dangers of Strep Throat
Often a sore throat is not seen as a serious ailment. However, strep throat can lead to serious complications if left untreated, especially in severe cases or where the immune system is weakened. While there is always a risk of sepsis in any bacterial infection, the more specific complications seen with strep throat may include acute rheumatic fever and poststreptococcal glomerulonephritis.
Acute rheumatic fever (ARF) occurs 2 to 4 weeks after strep throat but is largely preventable with proper antibiotic treatment. In this condition, the infection ‘misleads’ the immune system which can then attack other organs beyond the throat, such as the heart.
Read more on rheumatic heart disease.
Poststreptococcal glomerulonephritis occurs 1 to 3 weeks after strep throat. Unlike acute rheumatic fever, it is not usually preventable with early antibiotic treatment. Similiar to strep throat, it is an inflammatory disorder that appears to be autoimmune in nature and may affect the kidneys.
Another rare but deadly complication following strep throat is streptococcal toxic syndrome. The toxin produced by the bacteria Streptococcus pyogenes may enter the bloodstream and be distributed throughout the body. This is more likely to occur and be severe in people who are unable to produce antitoxins.