Incision and drainage is the procedure of choice for subcutaneous abscesses.
Antibiotics are not necessary unless there is associated cellulitis.
Abscesses should be probed with curved hemostats to break up loculations and identify deeper tracks.
Local anesthesia may be difficult and require additional field block, parenteral analgesics, or sedation.
Incision and drainage (I&D) is the definitive treatment for any subcutaneous abscess. Abscesses should be drained if larger than 5 mm and accessible to percutaneous incision. Antibiotics alone are not adequate treatment of an abscess. In fact, skin abscesses without surrounding cellulitis, once drained, do not require any further treatment with antibiotics.
Abscesses can be diagnosed by physical examination based on swelling, pain, redness, and fluctuance (Figure 1-1). Some abscesses will spontaneously drain, leaving little diagnostic doubt. Bedside ultrasound may aid in diagnosis by identifying a hypoechoic area of fluid just under the skin. Needle aspiration may also be employed to prove the presence of pus.
A subcutaneous abscess in an intravenous drug user.
Abscesses are often denoted by various names depending on their location and/or structure involved. The treatment remains the same. Paronychia and eponychia form around the nail (Figure 1-2). Felons occur with infection of the volar pad of the finger and require a specific approach for drainage. Bartholin gland abscesses occur in the paired glands that provide moisture to the vestibule of the vaginal mucosa. When the opening becomes occluded, either an abscess or a cyst can develop. After I&D, a Word catheter is placed to insure continued drainage of the gland. Removal or marsupialization of the gland may be required to prevent recurrence.
Hidradenitis suppurativa is a chronic relapsing inflammatory process affecting the apocrine glands in the axilla, inguinal area, or both. Multiple abscesses can form and eventually lead to draining fistulous tracts that require surgical management. I&D of these abscesses is frequently necessary and performed in the emergency department.
Incision and drainage may also be used to treat infected pilonidal or sebaceous cysts. Further treatment by a surgeon will often include removing the capsule to prevent recurrence.
Perirectal abscesses include superficial abscesses (ie, perianal), which can be drained by emergency physicians, and deeper abscesses (ie, ischiorectal, intersphincteric, supralevator), which require operative surgical drainage. Perianal abscesses present as tender, fluctuant masses palpated around the anal verge. Deeper abscesses often present with rectal pain, pain with defecation, rectal and buttock erythema and tenderness, and systemic symptoms (ie, fever, lethargy).
Cellulitis without evidence of underlying abscess should not be incised. Pulsatile masses that may be infected pseudoaneuryms should not be incised.