Make a stab incision with a #11 scalpel blade in the skin overlying the area of fluctuance (Figure 111-3A). The incision should be parallel to any lines of tension to produce the least conspicuous scar, particularly in cosmetically important areas such as the face. Extend the incision the length of the fluctuant area with a #11 or #15 scalpel blade unless the abscess is in a cosmetically important area. A linear incision is adequate, although some advocate a cruciate incision (Figure 110-10). The cruciate incision results in greater scarring, however, and probably is not necessary. An elliptical incision can be performed in noncosmetically important areas (Figure 111-3B). The purpose of the elliptical incision is to remove a full thickness wedge of tissue so that the wound will remain open. Limit the length of the incision on cosmetically important areas to 3 to 4 mm. This is just large enough to drain the abscess.
Incision and drainage of an infected sebaceous cyst. A. A straight incision to drain the abscess. B. An elliptical incision to drain the abscess. C. The wound is irrigated with sterile saline. Pockets of purulent material are opened with the hemostat. D. The wound is packed open.
Express the pus and the sebaceous material. It is too thick to drain spontaneously. It is important that loculations be lysed and the area be thoroughly drained to minimize recurrence. Insert a hemostat and spread the jaws within the cavity (Figure 111-3C). Useful technique employs gauze clamped in the jaws of a hemostat and swirled inside the abscess cavity to break adhesions and remove debris. Irrigate the cavity with normal saline (Figure 111-3C).
Loosely pack the wound cavity with ribbon gauze or gauze squares to prevent the skin edges from closing prematurely if a linear incision was made (Figure 111-3D). Cruciate and elliptical incisions do not require packing of the wound. Cover the wound with a bulky gauze dressing to soak up continued drainage.
Incision and Drainage with Primary Cyst Removal
The entire sebaceous cyst, including the capsule, can be removed at the time of the incision and drainage with a simplified technique.6 Make an incision in the skin overlying the center of the sebaceous cyst. Extend the incision to be slightly longer than the diameter of the sebaceous cyst. Do not cut into the dermis or subcutaneous tissues. Sharply dissect the sebaceous cyst free of the surrounding subcutaneous tissues with an iris scissors. The delineation between the thin, shiny, white capsule and the surrounding tissues is very obvious. Do not puncture the capsule of the sebaceous cyst. Doing so and spilling some of the contents sets up a nidus for subsequent infection or reformation of the sebaceous cyst. Start at both ends of the incision and free the cyst circumferentially. Once the sides of the cyst are free from the surrounding adipose tissue, gently grasp the top of the cyst with a hemostat or forceps and gently elevate it. Dissect the inferior border of the cyst free until it can be removed. Irrigate the wound with at least 200 mL of normal saline solution. Allow the cavity to heal by granulation. Alternatively, close the pocket with 3-0 Vicryl deep sutures and approximate the skin edges with nylon sutures.
The cyst capsule can often rupture when attempting to remove it intact. If this occurs, express the contents as if incising and draining an abscess. Gently flush the cyst cavity with normal saline. Grasp the shiny, cut edges of the capsule with a hemostat. Gently elevate the cyst capsule edges and dissect the complete cyst capsule free from the surrounding adipose tissue. Irrigate the wound with at least 200 mL of normal saline solution. Allow the cavity to heal by granulation. Alternatively, close the pocket with 3-0 Vicryl deep sutures and approximate the skin edges with nylon sutures.
Submit the complete cyst and capsule or the ruptured capsule for pathologic diagnosis in a sterile container. Several pathologic conditions can mimic a sebaceous cyst. This includes adenomas, adenocarcinomas, dermoids in children, and melanomas. Preauricular tender masses can be parotid gland tumors.
This technique results in fewer days to heal, less pain for the patient, and less scarring than with incision and drainage alone.6 This was not a blinded study and no other studies could be found to verify their results. The researchers noted that primary resection (average of 50 minutes) takes longer than simple incision and drainage (average of 10 minutes). This may limit its use in the Emergency Department.