HI, thanks for using healthcare magic

It would be best not to puncture it because the aseptic technique can introduce further infection.

At the moment, it is likely that you have an abscess which is a localized collection of pus, though part of treatment is incision and drainage of the abscess, this should done aseptically to prevent worsening.

In addition, the abscess cavity is supposed to explored or prodded for a bit to break down any additional pus walls to prevent recollection.
It would be best to see your doctor for assessment and treatment.
Antibiotics are also needed

If this is difficult at this time then you can consider magnesium suphate paste, this encourages discharge to come out of an abscess.

I hope this helps

I would recommend against using any needles, you can potentially inoculate the wound and promote a worsening infection. I am curious as to your past medical history, diabetes? Did you hit or scrap your knee recently? Do you have hairy legs (consider folliculitis)? These questions can be helpful to interpret the etiology of your wound as this is not a typical place to spontaneously develop an abscess, which is what I believe you are describing. The best treatment is to get evaluated by a doctor in person. If it is necessary you might have a sterile procedure to drain the fluid collection but this should only be done by a healthcare professional. Antibiotics like Keflex or Clindamycin might be necessary. Are you having any knee pain, swelling or redness?

Until you are evaluate by a physician, I would recommend warm compresses, simply use warm water or a warm, clean guaze or towel to apply gentle heat to the lesion. This will naturally bring the pus to the surface and allow for spontaneous discharge.

Marco Zahedi, MD
Family Medicine