Signs and Symptoms of Abscess

An abscess refers to a collection of infected fluid, commonly known as pus, usually associated with inflamed tissue, which gets red, swollen, warm and painful. Abscesses can occur anywhere on or in the body, though most frequently are located just under the skin in subcutaneous tissues. An abscess develops when bacteria get through our natural barriers to infection, like the skin, and grow and multiply, causing infection. The dead bacteria, dead tissue, blood and body fluids containing infection-fighting cells all collect in the area, leading to a pocket of creamy, foul-smelling pus that gets bigger, putting pressure on the swollen tissue around it and causing pain.

The infection also brings more blood to the area, making the tissues look red. Sometimes the skin and soft tissue nearby feel firm to the touch, though the center of the infected pocket may feel soft, like a fluid-filled bubble. Local pain and tenderness are likely to increase over time; however, if the pus can escape through even a small hole in the skin, evacuating part or all of the abscess, the pressure and pain may be relieved.

If the abscess is not opened and the pus drained out, the infection generally spreads deeper and wider into the tissues, and the bacteria can get into the patient’s bloodstream, causing a whole-body infection. The patient may have a fever and/or chills. Other abscesses can form, if the patient touches the infected area and transfers bacteria to another area of the skin, especially skin which is irritated, cracked or injured.

Common sources of skin abscesses are injections (insulin shots, IV drugs, skin popping), ingrown or infected hair follicles (like after shaving), or injury with a dirty object (plant or gardening tool, insect/animal/human bite)—all of these involve a break in the skin, where bacteria can enter and flourish. Other types of abscesses include perirectal (occurring near or around the anus, usually developing from normal bacteria in the tissues surrounding the anal canal) and pilonidal (located over the tailbone at the top of the crease between the buttocks).

Diagnosis of Abscess

The doctor will take a careful history, asking about when and how your symptoms started, like pain, swelling and/or drainage, where they are located, and whether there have been changes since starting. A physical examination enables your doctor to evaluate for presence and degree of tenderness, redness, warmth or swelling. Blood may be drawn to check labs related to infection and other possible causes of your symptoms. Imaging may be performed, either ultrasound, which can help identify fluid under the skin, or a CT scan, which can show the doctor the location and extent of the abscess. Even without imaging, though, most abscesses can be diagnosed on physical exam by their characteristic appearance.

Treatment for Abscess

Antibiotics are commonly prescribed for the tissue inflammation, redness and swelling known as cellulitis, but the treatment for abscess is drainage of the pus. An incision is made in the skin, sometimes with removal of a small piece of inflamed or dead tissue, to access the infected fluid and let it out. Culture of the fluid may be sent to the lab to identify the bacteria causing the infection and guide antibiotic therapy. The skin is numbed before the incision with injections of local anesthetic, though if the abscess is large or extensive, a surgeon may perform the procedure in the operating room, with more sedation or general anesthesia, while the patient sleeps. Once the pus is all out, the cavity will be packed with gauze and covered with a dressing. The wound will be cared for daily, by removing the packing, cleansing the cavity, and repacking it with gauze. The wound will heal from the inside out, over time. A visiting nurse may come to the patient’s home to help with wound care after discharge from the hospital, or a family member may be able to help with dressing changes. Pain medication is used to manage the discomfort, which should lessen every day, as the wound heals.