An abscess is a confined collection of pus surrounded by inflamed tissue. Most abscesses are found on the extremities, buttocks, breast, axilla, groin, and areas prone to friction or minor trauma, but they may be found in any area of the body. Abscesses are formed when the skin is invaded by microorganisms. Cellulitis may precede or occur in conjunction with an abscess. The two most common microorganisms leading to abscess formation are Staphylococcus and Streptococcus. Perianal abscesses are commonly caused by enteric organisms. Gram-negative organisms and anaerobic bacteria also contribute to abscess formation.
Treatment of an abscess is primarily through incision and drainage (I&D). Smaller abscesses (<5 mm) may resolve spontaneously with the application of warm compresses and antibiotic therapy. Larger abscesses will require I&D as a result of an increase in collection of pus, inflammation, and formation of the abscess cavity, which lessens the success of conservative measures.
Untreated abscesses may follow one of two courses. The abscess may remain deep and slowly reabsorb, or the overlying epithelium may attenuate (i.e., pointing), allowing the abscess to spontaneously rupture to the surface and drain. Rarely, deep extension into the subcutaneous tissue may be followed by sloughing and extensive scarring. Conservative therapy for small abscesses includes warm, wet compresses and anti-Staphylococcal antibiotics. I&D is a time-honored method of draining abscesses to relieve pain and speed healing. Routine cultures and antibiotics are usually unnecessary if an abscess is properly drained.
After I&D, instruct the patient to watch for signs of cellulitis or recollection of pus. Train patients or family to change packing, or arrange for the patient’s packing to be changed as necessary. Cellulitis occurs most commonly in patients with diabetes or other diseases that interfere with immune function. I&D of a perianal abscess may result in a chronic anal fistula and may require a fistulectomy by a surgeon.
Skin prep material (chlorhexidine [Hibiclens] or iodine swabs)
No. 11 or 15 blade and scalpel
Packing (plain or iodoform) ribbon gauze
Dressing (4- × 4-inch gauze pads and tape)
Palpable, fluctuant abscess
An abscess that does not resolve despite conservative measures
Large abscess (>5 mm)
Extensively large or deep abscesses or perirectal abscesses that may require surgical debridement and general anesthesia
Facial abscesses in the nasolabial folds (risk of septic phlebitis secondary to abscess drainage into the sphenoid sinus)
Hand and finger abscesses should receive surgical or orthopedic consultation
Use caution with immunocompromised patients and diabetic patients; these populations may require more aggressive measures and follow-up.
Prep the surface of the abscess and surrounding skin with povidone-iodine or chlorhexidine solution (see Appendix E) and drape the abscess with sterile towels. Perform a field block by infiltrating local anesthetic around and under the tissue surrounding abscess.
PITFALL: The environment of an abscess is acidic, which may cause local anesthetics to lose effectiveness. Use an appropriate amount of anesthetic, and allow adequate time for anesthetic effect.
PITFALL: Avoid injecting into the abscess cavity, because it may rupture downward into the underlying tissues or upward toward the provider.
Make a linear incision with a no. 11 or 15 blade into the abscess.
PITFALL: The most common cause of abscess reoccurrence is an incision not wide enough to promote adequate drainage.
PITFALL: Inform the patient before the procedure that scarring is possible.
PITFALL: Contents of the abscess may project upward and outward when it is incised, especially if local anesthetic was inadvertently injected into (instead of around) the abscess. Use personal protective equipment to avoid self-contamination.
Allow purulent material from the abscess to drain. Gently probe the abscess with the curved hemostats to break up loculations. Attempt to manually express purulent material from the abscess.
Insert packing material into the abscess with hemostats or forceps. Dress the wound with sterile gauze and tape.
Pain during and after the procedure
Reoccurrence of abscess formation
Damage to nerves and vessels
Skin abscesses in children should be approached the same way as for adults. Consideration should be given to pediatric antibiotic dosing if choosing to treat the abscesses with conservative measures.
The patient should be instructed to keep the wound clean, dry, and covered with absorbent material. If the abscess contains packing gauze, instruct the patient to remove packing material and repack the abscess every 1 to 2 days until the abscess cavity has resolved and packing materials can no longer be inserted into the abscess. If the patient does not feel comfortable with repacking, direct the patient to a medical facility for repacking of the abscess every 1 to 2 days. Instruct the patient to change the overlying dressing once a day. Inform the patient that he or she may take over-the-counter pain relievers or prescription pain relievers as directed for pain.