Incision and Drainage

Key Points

• Incision and drainage is the procedure of choice for

subcutaneous abscesses.

• Antibiotics are not necessary unless there is associated

cellulitis.

INDICATIONS

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 cel ­

lulitis, once drained, do not r equire 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.

Abscesses are often denoted by various names depending on their location and/or structure involved. The t reatment 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.

1

• 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.

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

.A. Figure 1-1. A subcutaneous abscess in an intravenous

drug user.

CHAPTER 1

Figure 1-2. Paronychia.

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).

CONTRAINDICATIONS

Cellulitis without evidence of underlying abscess should

not be incised. Pulsatile masses that may be infected pseudoaneuryms should not be incised.

Extremely large or deep abscesses should be considered

for drainage under anesthesia. As a result of transient bacteremia, those patients at risk for endocarditis owing to an

artificial or abnormal heart valve should be given appropriate perioperative antibiotics.

Abscesses of the palms, soles, nasolabial fold, breasts,

finger pads (felons), face, and deeper perirectal region can

be associated with complications. Consider consultation

with the appropriate surgical subspecialty.

EQUIPMENT

Povidone-iodine solution or chlorhexidine solution to

cleanse the skin

Anesthetic of 1 o/o lidocaine or 0.25% bupivacaine with

epinephrine

1 8-gauge needle (to aspirate anesthetic)

27-gauge needle and syringe (to inject local anesthesia)

Splash guard or 1 8-gauge angiocatheter (without needle)

30-mL syringe for irrigation

Sterile water or normal saline

1 1-blade scalpel

Swab for bacterial culture

Curved hemostat

;4-inch iodoform packing

Scissors

Gloves, gown, and facemask with shield (universal

precautions)

Gauze and tape

PROCEDURE

Discuss the risks and benefits of the procedure with the

patient before obtaining consent. Verify abscess location

with ultrasound if necessary. Wash your hands and wear

gloves, gown, and a face shield, as many abscesses are under

pressure. Position the patient and lighting to allow for the

best visualization and access to the abscess. Prepare the

area with povidone-iodine solution or chlorhexidine.

Utilizing a 27-gauge needle, inject the anesthetic j ust

under the dermis parallel to the surface of the skin.

Blanching of the tissue will occur as the anesthetic spreads

out through the skin. Cover the entire area to be incised.

Avoid injecting lidocaine into the abscess cavity. This may

increase the pressure in the cavity causing more pain. For

larger abscesses, local field blocks, parenteral analgesics,

and/or procedural sedation may be necessary.

If it is unclear whether an abscess exists, attempt aspiration of pus with a syringe and an 18- or 20-gauge needle.

If confirmed, use an 1 1-blade scalpel to make a single incision in the skin. The incision should be at the point of

maximal fluctuance oriented in the long axis of the abscess.

In general, the incision should extend two thirds of the

diameter of the abscess cavity ( except when draining

Bartholin gland abscesses, for which only an incision

0.5-1 em should be made). Attempt to incise parallel to

existing skin tension lines to promote cosmetic results.

Use gentle and steady pressure around the abscess to

express pus from the cavity. Insert a curved hemostat to

break loculations by working in a clockwise fashion

around the entire abscess cavity. This will also help identify

any deeper tracks. If desired, obtain a culture of the wound

at this time.

Consider gentle irrigation of the wound until the fluid

returning is clear. Pack the wound with enough iodoform

gauze to keep the sides of the abscess from touching. This

will allow for further drainage. Cover the wound with

gauze.

When treating a Bartholin gland abscess, a small catheter (Word catheter) is placed in the opening instead of

iodoform. The catheter should remain in place for several

weeks to allow for the development of a fistula for continued drainage.

I NCISION AND DRAINAGE

The patient is instructed to follow up in 48 hours to

have the packing removed. If pus is no longer present and

symptoms are resolving, the wound is allowed to heal by

secondary intention.

COMPLICATIONS

Scarring from the abscess and incision will occur. Numbness

from cutaneous nerve injury may occur. Seeding of the

blood with bacteria may transiently occur.

SUGGESTED READING

Fitch MT, Manthey DE, McGinnis HD, et al. Abscess incision

and drainage. N Eng! J Med 2007;357:e20.

Hankin A, Everett WW. Are antibiotics necessary after incision and

drainage of a cutaneous abscess? Ann Emerg Med. 2007;50:

49-5 1.

Kelly EW, Magilner D. Soft tissue infections. In: Tintinalli JE,

Stapczynski JS, Ma OJ, Cline DM, Cydulka RK, Meckler GD.

Tintinalli's Emergency Medicine: A Comprehensive Study Guide.

7th ed. New York, NY: McGraw-Hill, 20 11: Pages 1014-1024.