Brief Answer:
Request an Image

Detailed Answer:
Hello. Thank you for writing to us.

I have taken note of your query and I wish to answer it to your satisfaction.

Blister on an old scar could be due to trauma Or due to a skin infection.

Unfortunately I have'nt recieved any Image. I would require an Image so that I am able to guide you better.
You may try to upload an Image either at "Reports Section" Or You may also mail me an Image at YYYY@YYYY with the subject line as 'Attn:Dr. Kakkar'.

Regards

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Brief Answer:
Either puncture it under aseptic conditions Or leave it slone as it is

Detailed Answer:
Hi. Thank you.

I apologize for some delay in my reply due to prior commitments.

I have reviewed the Images. Yes, it is a blister and it looks like it is filled with clear fluid. The reason it could have formed is likely secondary to trauma/ scratching/ rubbing etc.

There are 2 ways you can go about this.

1. If I was the treating doctor I would puncture it with a sterile needle and allow it to drain away. You may do this yourself but before puncturing I suggest that you clean the area with soap water and wash your hands thoroughly. Thereafter you may puncture it wth a STERILE NEEDLE, at its most dependent part and allow its fluid to drain away. Make sure you don't peel-off roof of blister as this would act as a sterile dressing.
Subsequently, you may use an OTC topical antibacterial e.g 2% mupirocin ointment, twice daily.

2. Alternatively, you may leave it, as it is, and just use a topical antibacterial ointment, twice daily.
However, if it keeps expanding then I would suggest you to go by step no. 1 i.e puncturing it with a sterile needle under aseptic conditions.

Regards

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Brief Answer:
Skin blister is not connected to knee infection

Detailed Answer:
Hi.

Not at all. This skin blister could not have come from a knee joint infection.

Regards

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