An infected cyst is painful, swollen, and sometimes leaking foul-smelling fluid, and most cases need professional drainage to fully resolve. While warm compresses can help with mild symptoms, a true infection typically requires a doctor to open and drain the cyst, and sometimes a course of antibiotics. Here’s what to do and what to expect at each stage.
Infected vs. Inflamed: What You’re Dealing With
Not every angry-looking cyst is actually infected. Cysts can rupture beneath the skin, spilling their contents into surrounding tissue. This causes redness, swelling, and pain that looks a lot like infection but is really just inflammation. The key differences matter because they change what treatment you need.
An inflamed cyst is red, tender, and swollen but typically lacks pus or drainage. An infected cyst produces those same symptoms plus yellow, foul-smelling fluid, increasing warmth around the site, and sometimes fever. If the skin over the cyst is thinning and developing a visible white or yellow point, that’s a sign pus has collected and the infection is ready to be drained. Inflammation alone often settles down with warm compresses and time. Infection usually does not.
What You Can Do at Home
For a cyst that’s mildly inflamed or in the early stages of infection, warm compresses are the most effective home treatment. Apply a clean, warm (not hot) washcloth to the area for 20 to 30 minutes, 3 to 4 times a day. The water should be comfortable bath temperature, not scalding. This increases blood flow to the area, helps your immune system fight the infection, and can encourage the cyst to drain on its own.
Keep the area clean with gentle soap and water. If the cyst starts draining on its own, let it. Don’t squeeze it, pop it, or try to lance it with a needle. Squeezing pushes bacteria deeper into the tissue and can spread infection to surrounding skin or, in extreme cases, into the bloodstream. It also causes scarring. Cover any draining cyst with a clean bandage and change it when it gets wet or soiled.
When Home Care Isn’t Enough
Warm compresses work well for minor inflammation, but they have limits. If the cyst is growing larger, becoming more painful over several days, producing pus, or if you develop a fever, it’s time for professional treatment. Red streaks spreading outward from the cyst are a sign that infection is moving into surrounding tissue, and that needs prompt medical attention.
An infection that spreads from a cyst into the surrounding skin (cellulitis) can become serious quickly. Warmth, expanding redness, and feeling generally unwell are all signals that your body isn’t containing the infection on its own.
How Doctors Drain an Infected Cyst
The standard treatment for an infected cyst with a pus collection is incision and drainage, a minor procedure done in a doctor’s office or urgent care. It’s quick, usually taking 15 to 20 minutes, and you go home the same day.
Your doctor numbs the area with a local anesthetic injected around the cyst. If the skin over the cyst is very thin and inflamed, they’ll place the numbing injections in a ring around the cyst rather than directly into it, which is more effective and less painful. Once the area is numb, the doctor makes a small cut along the top of the cyst, expresses the pus, and cleans out the cavity. In the past, doctors routinely packed the wound with gauze strips, but current evidence suggests packing isn’t always necessary.
You’ll leave with an absorbent bandage over the wound. The whole experience feels like pressure rather than sharp pain once the anesthetic kicks in.
Antibiotics and When They’re Needed
Drainage alone clears most infected cysts. Antibiotics are added when the infection has spread beyond the cyst itself, when you have a fever, or when you have a weakened immune system. Your doctor makes that call based on how the infection looks and how you’re feeling overall.
When antibiotics are prescribed, they typically target the bacteria most commonly found in skin infections. The specific antibiotic depends on whether your doctor suspects a standard skin bacteria or a resistant strain like MRSA. Common options include cephalexin for standard infections and drugs like doxycycline or trimethoprim-sulfamethoxazole when MRSA is a concern. You’ll typically take them for 7 to 10 days. Finish the full course even if the cyst looks better after a few days.
Recovery After Drainage
The wound from an incision and drainage heals from the inside out, which means it’s left open rather than stitched closed. This feels counterintuitive, but closing an infected wound traps bacteria inside and leads to reinfection. Expect the wound to take 1 to 2 weeks to fully heal, depending on the size of the cyst.
If your doctor placed packing inside the wound, you’ll return in a day or two to have it removed or replaced. Once packing is out, wash the area gently in the shower once a day until the skin opening closes, which typically takes up to 5 days. Keep the wound covered with a clean, dry bandage between washings. Some drainage and mild soreness in the first few days is normal. Increasing pain, expanding redness, or new fever after the procedure is not.
Preventing Recurrence
Here’s something many people don’t realize: draining an infected cyst treats the infection, but it doesn’t remove the cyst itself. The cyst wall, a thin sac of tissue under the skin, remains in place. As long as that sac is there, the cyst can refill and potentially become infected again.
To permanently eliminate a cyst, the entire sac needs to be surgically removed. This is a separate, minor procedure, but it can’t be done while the cyst is actively infected. The tissue is too swollen and fragile to cleanly separate from surrounding skin. Doctors typically wait about one week after the inflammation has fully subsided before scheduling excision. If you’ve had repeated infections from the same cyst, this removal is worth discussing with your doctor.
Between episodes, avoid picking at, squeezing, or irritating the cyst. Keep the skin over it clean, and watch for early signs of inflammation so you can start warm compresses before a full infection develops.