Medical Fun Facts Episode 73: PANDAS

Hello, friends, this is the last Medical Fun Facts post on this site. I've transferred the blog posts and podcast to another platform. Please continue enjoying The Medical Fun Facts Podcast over at 

It’s Monday 03 July 2017.

Thanks for subscribing and listening to Medical Fun Facts.

Show notes are available at

Tonight’s show is inspired by a friend’s status update on Facebook. My friend is holidaying on a resort in a country which doesn’t regulate drugs in the same way as we do in Australia, the United States, Canada and the UK, you know the like-minded nations.

My friend mentioned she had a sore throat and could buy antibiotics over the counter without a prescription.

I asked what she bought and she replied amoxicillin (Amoxil™).

This raised a few concerns

Most pharyngitis or sore throat is caused by a viral infection. It’s often associated with those viruses that cause head colds. Amoxil is not going to kill viruses. Secondary bacterial infections of the pharynx rarely occur so that’s not a good reason to take Amoxil either.

The Amoxil will be swallowed, absorbed and distributed through the body. Any resident bacteria, especially bowel bacteria will be exposed and through natural selection, susceptible good bacteria will be killed and resistant bacteria will remain. This could potentially, create an imbalance that if other factors are present could lead to colonisation with drug-resistant bacteria. Should the person suffer an injury, say a burn or a significant soft tissue injury of a lower limb, the drug-resistant bacteria may colonise and then infect the wound. This is not a good outcome.


The other problem with Amoxil is that if the sore throat was part of an infectious mononucleosis and the cause is the Epstein-Barr virus, Amoxil commonly results in a rash which sometimes can be quite severe. While this reaction may be allergic-like, it does not result in true allergy. So the problem we face is that a patient may suffer a rash and sometimes that rash can be quite severe. The patient may also come away with the mistaken belief that he or she is allergic to Amoxil and every time he or she needs an antibiotic, he or she may state this with such confidence, that a simple infection that could be treated with Amoxil may be treated with something more potent and more expensive. In some situations, doctors will assume the patient is allergic to all beta-lactam drugs making a whole class of valuable medication unavailable on a misunderstanding.

There’s a basic principle for sore throats. The vast majority are caused by pathogenic viruses for which there are no effective and cheap drugs. The one bacteria we all worry about is Streptococcus pyogenes or the Group A streptococci (GAS for short). There is no way by just looking into someone’s mouth to tell if the cause of the sore throat is Streptococcus pyogenes. The presence or absence of pus is generally meaningless. The only reliable method is to refer the patient for a diagnostic test. This can be culture or any of the newer reliable methods.

The classical treatment in patients who are not allergic to penicillin is penicillin for 10 days. In fact, if we know the cause is definitely group A streptococci, then Amoxil is fine too. The duration is important because the aim is to reduce the opportunity for post-infectious immunological sequelæ like glomerulonephritis and rheumatic fever.

However, it’s not known if antimicrobial therapy will change the incidence of PANDAS or Pædiatric autoimmune neuropsychiatric disorder associated with group A streptococci. PANDAS is an observation that in children with group A streptococcal infection, they may be prone to obsessive-compulsive disorders and tics. That is, T I C S which are spasmodic muscle contractions and not T I C K S the eight-legged blood eating arachnids. 

Medical Fun Facts Episode 73 PANDAS

Medical Fun Facts Episode 73 PANDAS

And so, ends another episode of Medical Fun Facts. If you have suggestions or requests for future shows please let me know. You can find the show notes for every episode at my blog

You can find updates in the Facebook page. You can get the address in the show notes. Feel free to like and share each show.

If you think more people would enjoy this show, please head over to iTunes and give Medical Fun Facts a 5-star rating and please leave a comment. By doing so iTunes will rank the show higher and make it easier to find.

Medical Fun Facts is also on Stitcher so if you use an Android device, you can download the Stitcher app and listen to the show in Stitcher. Android users should be able to find the Stitcher app in the Google Play store.

Like iTunes, if you visit the show on the Stitcher website and leave a review, the Stitcher algorithms will improve the show’s ranking and more people will be able to find it. Feel free to share the link via Facebook, Twitter, Google+ and any other social media platform.

If you disagree with anything in these podcasts or if you would like to voice a different view, please feel free to write a comment. If I have said something incorrect I welcome correction. Please also feel free to share your comments on social media.


Just remember, for shows with video I go off script for good portions so please listen or watch to catch everything not written in the blog post.

The video can be found at

Tweet me at

Send me a comment on Facebook at

E-mail me at