Group A streptococcus – bacterial pharyngitis or tonsillitis
One of the most common infections in children, and a common reason for antibiotic therapy. Though the disease is known from the early days, there is still much confusion about it.
The references for this post are diverse; from the official guidelines of the American Academy of Pediatrics on 2012, the red book of infectious disease and mostly from personal experience.
So how do you call this disease? Pharyngitis or tonsillitis?
The definition is basically very similar. Pharyngitis – redness and pain in the posterior pharynx. Tonsillitis – redness, pain and sometimes exudates on the tonsils.
There is a clinical difference between these two conditions. There is a difference between a throat that is a little red, than tonsils that are white and purulent. In this post I will use the term pharyngitis to describe the spectrum of these infections.
What causes pharyngitis in children and adults?
Pharyngitis is mainly caused by viruses, mostly respiratory viruses but also EBV and CMV, which usually cause an illness known as mononucleosis. The minority of cases is caused by bacteria, mainly group A Streptococcus.
What are the clinical manifestations of strep pharyngitis?
Strep pharyngitis usually develops quickly, with symptoms including fever, headache, dysphagia and abdominal pain. There can be a characteristic voice called “Hot potato voice”. Characteristic rash may appear and may indicate the development of Scarlet fever.
During examination of the pharynx you would find prominent redness of the posterior pharynx, swelling and white exudate covering the tonsils. Enlargement and tenderness of the lymph nodes in the cervical area is common.
Lack of fever and symptoms such as – cough, runny nose, conjunctivitis or hoarseness usually indicate a viral infection rather than a bacterial etiology.
What is the common age for Strep pharyngitis?
The disease is common mostly between 5-15 years of age, but may appear before and after. Many parents suffer from strep pharyngitis, and here and there I see grandmothers who received this “gift” from their grandchildren.
The disease is not common before the age of 3 years old. I can say that there are exceptions, with strep infection diagnosed already at the age of 2 years. These are not common cases, and it is usually a child with an older siblings or with children over the age of 3 in their educational facility. But these cases are the exception.
If your physician obtains a throat culture for strep in a child under the age of 2 (or worse, prescribed antibiotics without a throat swab), try to understand the reason, because this is usually a mistake – Even If the swab came back positive – read ahead.
Can the physician (or the mother) look into the pharynx and declare with confidence on the pathogen?
Definitely no. This is doomed for failure. Even if a trained physician or mother would look into the pharynx and think to themselves that it looks just like strep pharyngitis (or any other pathogen), it will not be an accurate identification.
For example – EBV pharyngitis could be identical (at least by appearance) to strep pharyngitis.
There were many attempts in the past to find scoring systems that can predict which child suffers from strep pharyngitis, but the prediction value is relatively low. Therefore there is always a need for a microbiological specimen for correct diagnosis – a throat swab.
What kind of throat swabs are there?
A rapid throat swab and a regular throat culture.
Rapid swab – the main advantage is that you get an answer instantly. A positive swab confirms the presence of group A strep in the pharynx. This swab is 70%-90% accurate, there for a negative swab calls for a regular throat culture. This is the only place in this post, where management in adults will be different than in children – allegedly, as per the official recommendations in adults, there is no need for a regular culture if the rapid swab is negative.
Regular throat culture – considered to be the gold standard, and most accurate test. The problem is the time until receiving answers (about 2 days).
How to take throat swabs in children?
In order to lower the prevalence of a false negative answer, a professional must take the swab.
I know that many parents do the rapid swab at home. If the test is positive – there is group A strep in the child’s pharynx.
If it is negative, and there is reasonable suspicion for group A strep, go and see a professional to obtain another test.
My emphasis for taking the swabs is a real contact of the swab from both tonsils and the posterior pharynx as well. In many children there is need for lowering the tongue by a wooden tongue depressor.
Since the posterior pharynx is impossible to reach without lowering the tongue, a touch of the swab with the tongue is one of the reasons for a false negative answer. You can also use a dedicated instructions for taking a throat swab in this link.
A word of advice for parents taking the rapid test at home – please read the following paragraph. The fact that there is strep in the pharynx does not mean the child has strep pharyngitis. Please refrain from unnecessary tests and unnecessary antibiotics.
So, if there is a positive throat culture, does the child have strep pharyngitis?
A complex answer.
There is high percentage of carriers in the population (about 15%). So if a child with a runny nose and a bit of redness in his throat, which looks like a viral infection, would be tested by his physician with a throat culture – there is a 15% chance for finding strep in his pharynx, the same as the rate of carriers in the whole population. So taking that swab would lead to unnecessary treatment.
So how can we differentiate being a carrier from being ill? At the end there is a need to take a swab only from children suffering from an acute infection that can be explained by group A strep: being in the right age and with typical clinical findings.
Taking a swab by your physician is saying that there is a real chance of strep infection that requires treatment in positive cases. So there is no need for taking unnecessary throat culture in children where there is no clinical suspicion for strep throat, or as per the request of the parents.
What is the preferred treatment for strep throat?
In those without a known allergy for penicillin, treatment is a simple penicillin (Amoxicillin, Penicillin V, etc.). Group A strep does not have any resistance to penicillin, so there is no need in trying different antibiotics. Meaning:
– There is no advantage for treating with Amoxicillin-clavulanate over penicillin (just disadvantages).
– There is no advantage for treating with Azithromycin (unless in case of known allergy for penicillin)
– There is no advantage for treating with Cephalosporin over penicillin (just disadvantages).
I know people swear that their pharyngitis only passes when being treated with Amoxicillin-clavulanate and not with Amoxicillin alone. Most cases are just isn’t so.
Later on I will get to what to do with recurrent pharyngitis, but in short I will say that in those cases there is also no advantage for another antibiotic, just different management.
Why treat Strep pharyngitis?
There are several reasons:
– Shortening the duration of the disease. A child under treatment will get better faster.
– Preventing local complications, for example – tonsillar abscesses.
– Preventing infecting your surroundings – a child without treatment is very contagious.
– Preventing immunological complications – mainly rheumatic fever (cardiac and an articular involvement after a strep infection that wasn’t treated properly). Though it is a rear complication, it is not pleasant. A child with the right treatment will not have rheumatic fever.
When to start treatment if there is suspicion for strep pharyngitis?
If there is high clinical suspicion for strep pharyngitis, and if the rapid swab is positive, treatment should be started promptly.
If a regular culture was taken and an answer will only be available after 48 hours, there are 2 options:
– Starting treatment immediately, and deciding about continuing it after receiving a positive answer or stopping when receiving a negative answer.
– Waiting for an official answer and starting only after getting a positive answer.
I think that when there is high clinical suspicion, and when a child is suffering, there is a room for starting the treatment early, after obtaining a throat culture. When the symptoms are inconclusive, you may wait for an official answer.
Aside from shortening disease duration and suffrage, it is important to start treatment in the 9 days following beginning of symptoms, in order to prevent rheumatic fever.
What are the doses and what is the duration of treatment for strep pharyngitis?
It is a relatively low dosage (since the absorption is excellent and the pathogen is very sensitive). The dosage in Amoxicillin is 50 milligrams per every kilogram of body weight, divided twice a day. This is a pretty low dose for other infections and pathogens treated by Amoxicillin.
Practically, for every child or adult who weigh above 20 kilogram the dose is 500 milligrams twice a day. Those who think there is a need for three times a day or who likes to take two pills together in the first time, or any other kind of inventions – there is no need for that.
Another option is to take the whole daily dose together, as one dose. Meaning – instead of dividing the dose to two times a day, just take it all, one time every day.
Treatment is for 10 days. Many times the child will feel better the very next day after starting treatment, and the parents don’t remember why they are giving antibiotic after a week has passed. But meticulous treatment for 10 days is important, in order to eradicate the bacteria from the throat and preventing recurrent events.
In cases of scarlet fever, treatment is the same.
When to expect recovery after starting treatment in strep pharyngitis?
In children recovery is very quick. In up to 24-48 hours from beginning of treatment the child will feel much better.
In adults – a little longer.
Until the antibiotic will work its charm, I recommend not forgetting analgesics and antipyretics.
When does a child stops being contagious and can return to normal activity?
The child is not contagious after 24 hours of appropriate antibiotic treatment. In terms of returning to normal activity – very quickly, as soon as the child feels better and does not have a fever. There is no need to wait for finishing the antibiotic course in order to return to school or kindergarten. Also, the antibiotic does not weaken the child.
Is there a place for obtaining another throat swab when the 10 days of treatment are over?
Taking another swab in the end of treatment just to see if the strep was eradicated is not necessary, and in most cases represents an error in judgment and management of the case.
What to do if the infection returns?
Unfortunately, recurrent infections are common. It can be because of re-infection from a friend or from a family member which is a carrier or is ill, or even in cases were the bacteria wasn’t eradicated from the pharynx after 10 days of treatment.
In cases suspected for recurrent infection, we must repeat the same principles which guided us in the first diagnosis:
– Taking a throat swab only to those with the right clinical signs.
– Before starting another antibiotic course, you should get another rapid swab or a throat culture.
– A meticulous antibiotic treatment for whole 10 days, not stopping after the child is improving.
– The best antibiotic, even in recurrent cases is Penicillin. In my opinion, any other antibiotic is irrelevant and without any advantages.
Some children and families have a lot of recurrent strep pharyngitis. What to do?
First of all – a right diagnosis, clinical and microbiological.
In a carrier rate of 15% in the population, I can enter a classroom of 40 healthy children, take throat swabs from all of them and find group A strep in 6 of them. We must make sure that we are seeing clinical signs suggesting strep (mostly high fever and typical finding in throat examination), and a microbiological proof for strep.
In addition, if is it recurrent pharyngitis in a cyclic pattern of 3-6 weeks between attacks, we must consider a disease called PFAPA which is an inflammatory disease rather than infectious one. I’ve seen many children with so called “recurrent strep pharyngitis” when in fact it was not strep at all, only PFAPA. Treatment of PFAPA is a single dose of steroids in every attack. A lot of parents are going around saying that they also suffered from recurrent strep infections as children, where in fact they also had PFAPA.
In real, exceptional cases, about 1-2 times a year I get convinced that there are many infections going around the same household. Only in this situation I take swabs from the entire members of the family and considering treatment for carriers.
In these rare cases, treatment in carriers is 10 days of Penicillin and in the last 4 days an addition of another antibiotic called Rifampicin to facilitate eradication.
Tonsillectomy is not acceptable today for treating recurrent strep pharyngitis.
Here are the 10 most important rules for management of strep pharyngitis:
- Most pharyngitis is caused by viral pathogens.
- Strep pharyngitis is not common before the age of 3.
- Carrier rate are up to 15%, therefor, aside from exceptional cases, do not obtain throat culture from healthy children or with a mild symptoms of viral infection.
- Due to the fact that an accurate clinical diagnosis is difficult, when suspecting a real bacterial infection, you should obtain a rapid swab or throat culture.
- You should take the swab in an adequate way. If there is real suspicion for strep in a child, a negative rapid swab requires a regular throat culture.
- Treatment of choice in children and adults (without allergy for Penicillin) is a simple Penicillin for 10 days.
- There is no need for another swab or culture at the end of treatment.
- One should avoid identification and treatment of carriers.
- In recurrence of the disease, diagnosis and treatment must be done as in the first time. There is a need for a full 10 days treatment.
- In cases of recurrent pharyngitis, you should go to a specialist to diagnose if it is a case of recurrent strep pharyngitis or another medical condition (including PFAPA).