This complication is somewhat common, but, unfortunately, the piercing-friendly medical professionals I polled failed to come to a consensus on a diagnosis or suggested treatment. Therefore, I’ve named this complication based on its appearance and address it below using my professional piercing experience in conjunction with accepted health care principles. Overall, the symptoms are similar to those of folliculitis, which is an inflammation and infection in or near a hair follicle. However, this type of complication routinely occurs near the openings of nipple piercings, where hair follicles are not plentiful. 

Sometimes a pustule (a small round area of inflamed skin filled with pus) will appear under the skin near the opening of a piercing. It may be caused by trauma or a mild infection that remains contained locally. A small pocket forms close to the surface and repeatedly fills and drains. Sometimes it seems to be gone for good, but then the cycle begins once again, weeks or months later. The best way to resolve the problem appears to be by helping your body to break down and absorb the sac or pocket that has formed. You may be tempted to pop this pimple-like eruption yourself, but never lance your skin with nonsterile implements; use warm compresses to encourage drainage. If you have a localized pustule that won’t open or drain and needs to be lanced, seek medical assistance.. 

Identifying a Piercing Pimple
•    Small, slightly elevated pus-filled bump or pimple adjacent to the piercing 
•    Red and inflamed, but contained locally 
•    May be tender, itch, or burn, though some are painless 
•    Usually secretes pus and/or blood when drained (or popped)

What to Do for a Piercing Pimple
• NEW! Many piercees have had excellent results with this problem using Briotech. It is certainly worth a try.
•    Follow the suggestions under “What to Do for a Minor Localized Infection,” page 249.
•    Over-the-counter antihistamines taken according to package instructions can diminish itching and inflammation.
•    Do plenty of warm compresses. Continue them for two weeks after the problem seems to have been resolved.
•     When it looks improved, manually break up the pocket to prevent refilling by rolling the tissue surrounding it between your fingers. [In combination with compresses or other remedies, this is the one thing that seems to really help prevent recurrence.]
•    If you do not respond to treatment, lab analysis for an invading microorganism may be needed to determine if the cause is fungal or bacterial so your doctor can prescribe appropriate medication to target the problem.
•    You must see a doctor if you have increased pain, a fever over 100 ̊F (37.8 ̊C), or the infection worsens or spreads.
•    If you have a verified diagnosis of folliculitis, laser hair removal can destroy the hair follicle, prevent future episodes, and reduce the scarring of repeated eruptions.

Disclaimer: These suggestions are not to be considered a substitute for advice from a medical professional.