Use sterile scissors to clip the hair around the pustule.
Lance the pustule with a sterile narrow-gauge needle.
Collect the purulent exudate on a sterile swab.
Place collected material in a transport medium or sterile container.
Crust
Do not disinfect the surface.
Use sterile instruments (forceps or needle) to lift the edge of the crust.
Collect a sample with a sterile swab to the skin under the elevated crust.
Place collected sample in a transport medium or sterile container.
Epidermal Collarette
Do not disinfect the surface.
Use sterile scissors to clip hair.
Use a sterile swab to collect a sample by rolling it across the border of the collarette a few times.
Swab can be moisten to increase bacterial yield from epidermial collarettes 26
Place the collected sample in a transport medium or sterile container.
Papule
It can be possible to squeeze a small amount of inflammatory fluid from the papule.
Otherwise, collect a sample by performing a biopsy of the papule.
Provide local anesthesia.
Clip hair with sterile scissors or clippers.
Clean the skin surface with a single wipe of 70% alcohol and allow the alcohol to dry prior to sampling.
Use a sterile punch and surgical instruments to collect a sample of the papule.
Place tissue sample in a sterile container or transport medium.
Alternatively, a sample of the papule can be collected with a sterile needle inserted in the tissue and collecting the expressed blood or exudate. It is recommended to disinfect the papule as described prior to collecting the sample.