What Causes Painful Dark Blisters Behind Knee?

Posted on Sun, 4 Jan 2015

Medically reviewed by Ask A Doctor - 24x7 Medical Review Team

Sun, 4 Jan 2015 Answered on

Mon, 2 Feb 2015 Last reviewed on

Question : I believe that I have an outbreak of shingles but I am not certain. I have a cluster of blisters behind my right knee. It has not been about four days since the blisters have appeared which are now apparently free of puss. The skin is very dark and painful. This cluster has not spread and I have not other areas of outbreak. Does this sound like it might be shingles? If so what treatment should I begin? Does the vaccine help if I get a shot at this time?

Answered by Dr. Ivo Ditah (13 minutes later)

Brief Answer:
Please, provide an image!

Detailed Answer:
Hi and thank you so much for this query.

I am so sorry to hear about this rash and all the inconveniences this has caused you. The location of this rash is not typical of shingles and am not convinced this is shingles. I will like to see an image for inspection on order to tell what the rash is and make a list of possible causes. Depending on my thoughts on whether this is possible shingle or not, we would make a decision about vaccination/.

Look froward to hear from you. I Wish you well.

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar

Follow up: Dr. Ivo Ditah (8 minutes later)

What is the best way to send you an image of my rash?

Answered by Dr. Ivo Ditah (2 minutes later)

Brief Answer:
Look on the right and there is a link to upload, click on it!

Detailed Answer:
Hi,

On the right of your users interface, there is a link to upload files. Click on it and follow the instructions to upload an image.

I wish you well.

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar

Follow up: Dr. Ivo Ditah (22 minutes later)

I attached the image using the upload new reports tab and hopefully this was correct.
Thanks
XXXX

Answered by Dr. Ivo Ditah (37 minutes later)

Brief Answer:
Yes, that was correct!

Detailed Answer:
Hi,

This is not shingle. The location and nature of the rash is not suggestive. I recommend that you keep this area clean and dry. Cleanse daily with an antiseptic such as Iodine before applying the bacitracin ointment and zinc. This would lead to healing within a week.

I will not recommend an antibiotic right now. However, if the progress is not reassuring and as anticipated, we would consider doing so. Also, try exposing this area by avoiding to always get the knee in a flexed(bent) position.

Keep me updated within 48hours on progress.

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar

Follow up: Dr. Ivo Ditah (1 hour later)

If this is not shingles do you have any idea what might be the cause? I have started taking the Atorvastatin and Metoprolol about one month ago. Do you thing this could this be a side effect of either of these medications? I am at a complete loss as to what might have caused this problem. I did have a headache, which is rare for me, on the day I noticed the rash and I have had discomfort with the area around my eyes also lots of tearing.

Answered by Dr. Ivo Ditah (10 hours later)

Brief Answer:
Mot a side effect!

Detailed Answer:
Hi,

This looks like a bacterial soft tissue infection. It is not single and not a possible side effects of your medications. I will suggest that you monitor the progress and send more images for review and more recommendations.

I hope this helps and hope to hear from you in 48-72hours.

Note: For more detailed guidance, please consult an Internal Medicine Specialist, with your latest reports. Click here..

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar