What Causes Blisters On Back Of Throat?

Brief Answer:
Throat infection, drug reaction or low immunity

Detailed Answer:
Hi. It seems like these blisters could be due to an infection, reaction to medications or immune deficiency.

If I were your treating ENT specialist, I would evaluate for these three causes.

I would recommend a complete blood count which includes your white blood cell counts, differential counts and Erythrocyte Sedimentation Rate (ESR). This will give us a status on your immunity and also the nature of the infection (viral or bacterial). An examination of your Paranasal sinuses is also indicated since recurrent post nasal drip can lead to recurrent throat infections.

I would also like to evaluate the list of medications that you have taken recently in addition to what you have shared ( I have seen your medical history and clindamycin may lead to oral blisters and prednisone can lower your immune response)

You may also need a video endoscopy (using a 90 degree or 70 degree endoscopes) to have a closer look at the surgical site and the blister region to see if any tonsillar tissue or tag has been left behind.

Also note that stress can also precipitate oral blisters.

It is advised that you see your ENT specialist and discuss these suggestions. Also seek prescription for an antibiotic other than clindamycin, anti-inflammatory medications and oral antiseptic gargles before and after meals for 5 days. Keep your diet soft and bland and drink plenty of fluids (around 2 litres per day)

Hope this helps. Please do share your blood reports, medicine history and if possible an image of the blister to help me give further advise. Would like to follow up on your progress. Do reach out in case you need any further assistance.

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Brief Answer:
Medicine history contributory to oral blisters

Detailed Answer:
Hi. Thank you for writing back and sending this information. It would be great to have a look at the picture too. I didn't find it with your response.

Your medicine history since April shows the usage of medicines that can cause dryness of the mouth or oral/throat blisters or reduced immune response.

- Metronidazole can cause dryness of mouth, change in taste and oral throat blisters
- Citalopram is known to cause oral ulcers and sore throat
- Clindamycin may cause throat blisters
- Oral steroids such as prednisone and triamcinolone reduce immune response inspite of normal white blood cell counts

All of these may have affected healing (delayed) or allowed for repeated infection ( due to the steroids) leading to formation of recurrent blisters.

I would still advise a more comprehensive blood count analysis which includes WBC counts (prednisone has been taken the last few months and is known to reduce WBC counts), the differential count will point towards a bacterial (high neutrophils) or viral (high lymphocytes) infection and ESR to see if there is a chronic autoimmune condition that we are missing out on.

I do not note any medication that covers bacteria that infect the throat such as gram positive organisms which would respond better to a penicillin group of antibiotic (unless you are allergic then azithromycin would be next option). I am also unclear on why you need to be on oral steroids for so long unless there is some other reason to have you on those medications which we are not aware about. Do clarify this with your treating physician. A closer look at the surgical site with an endoscope will tell us if a tiny tag has been left behind which is the source of these recurrent blisters.

Please discuss these with your ENT and see if you can be tapered off the steroids and an oral antiseptic rinse such as chlorhexidine or betadine can be added as gargles. Also if a throat specific antibiotic can be added. You may continue with the antiviral to cover any viral pathology.

Please do keep me posted on your progress and let me know if I can help you with any further questions.

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