Can Internal Stitches Come to the Surface?

Internal stitches can and sometimes do migrate to the skin’s surface, a phenomenon surgeons call suture extrusion or “spitting sutures.” It happens when the body treats a buried stitch as a foreign object and gradually pushes it outward through the healing tissue. The experience is more common than most patients expect, and while it is usually more annoying than dangerous, knowing what to look for and when to act saves unnecessary worry.

Why Buried Stitches Work Their Way Out

When a surgeon places an internal stitch, it sits beneath the outer layer of skin, holding deeper tissue together while the wound heals. The body recognizes this material as something that does not belong. Immune cells, particularly macrophages, swarm the stitch and attempt to break it down or wall it off. In animal models, researchers have observed large, multinucleated immune cells clustering around suture material, essentially fusing together to attack something too big for a single cell to handle. The degree of this inflammatory response correlates with how much scar tissue forms around the stitch.¹

With absorbable stitches, this immune activity is part of the design. The body is supposed to dissolve the material over weeks or months. But sometimes the inflammatory reaction outpaces the absorption. Instead of quietly dissolving in place, the stitch gets encapsulated in a small pocket of inflammatory tissue and begins migrating toward the path of least resistance, which is usually the skin surface. Think of it like a splinter working its way out of your finger, except the splinter was placed there on purpose and sits deeper.

Non-absorbable internal stitches can surface too, though the timeline is different. Because the body cannot dissolve them, a persistent low-grade immune response may slowly push the material outward over months or even years. In either case, what the patient eventually sees is a small bump, a thread poking through the skin, or a tiny wound that will not quite heal.

Which Suture Materials Are More Likely to Surface

Not all stitch materials provoke the same immune reaction. The two big variables are whether the suture is absorbable or permanent, and whether it has a braided (multifilament) or smooth (monofilament) structure.

Braided absorbable sutures tend to trigger a stronger inflammatory response than smooth monofilament ones. Research on tissue reactions in oral mucosa found that multifilament suture materials caused more inflammatory tissue reactions than monofilament materials.² The braided structure gives immune cells more surface area to latch onto and creates tiny crevices where bacteria can hide, both of which amplify the body’s rejection response. This is one reason monofilament sutures are often preferred for internal closure, particularly in areas with delicate or thin tissue.

Absorbable sutures do carry some advantages. A systematic review of ten randomized trials comparing absorbable and non-absorbable sutures for surgical wound closure found that absorbable stitches led to a lower risk of wound breakdown.³ So while absorbable sutures can spit out, they may still be the better overall choice for many closures because the wound itself holds together more reliably. The trade-off is real but tilted in favor of absorbable materials for most situations.

Some commonly used absorbable sutures dissolve faster than others. Fast-absorbing gut sutures may lose their strength in under two weeks, while materials like polydioxanone (PDO) can maintain strength for months. A stitch that dissolves quickly has less time to cause extrusion, but it also provides less long-term support. Surgeons pick the material based on how much tension the wound is under and how long the deeper layers need reinforcement.

Where on the Body It Happens Most Often

Suture extrusion is not equally likely everywhere. Thin-skinned areas with little fat between the stitch and the surface are the prime spots. The face, scalp, hands, shins, and feet are frequent offenders. In these locations, there is simply less tissue to keep a buried stitch buried. Anywhere a wound is under significant tension, such as over a joint or along a scar that gets pulled with movement, also raises the risk. Tension pushes the knot upward over time.

Proper knot placement makes a significant difference. Surgical literature emphasizes that buried suture knots need to be anchored deep beneath the dermis to stay put.⁴ If a knot sits too close to the underside of the skin, even a modest inflammatory response can push it through. Surgeons sometimes use techniques specifically designed to bury the knot as deep as possible, particularly in cosmetic closures where a surfacing stitch would defeat the purpose of invisible repair.

The tissue type matters as well. Mucosal tissue, like the inside of the mouth, reacts more strongly to suture materials than tougher keratinized tissue like the gums.² This is relevant for anyone who has had oral surgery or internal stitches placed in areas with softer, more reactive tissue. The higher the baseline inflammation a tissue type produces, the faster it tends to reject foreign material.

What Suture Extrusion Looks and Feels Like

The first sign is usually a small, firm bump along the scar line that was not there before. It may be slightly red or tender. Some people describe a pricking or poking sensation, like a tiny thorn under the skin. As the stitch works closer to the surface, you might see a whitish or colored thread poking through the skin, sometimes with a drop of clear or slightly cloudy fluid around it.

Occasionally the area around the emerging stitch develops a small, persistent pimple-like bump that drains and then refills. This is the body forming a little channel around the stitch as it ejects it. The bump can look worryingly like an infection, but true infection involves spreading redness, increasing warmth, significant swelling, and sometimes fever. A spitting stitch is usually a localized nuisance confined to a spot the size of a pinhead or small pea.

The timeline varies widely. Fast-absorbing stitches may surface within two to four weeks of surgery. Slower-absorbing materials can take three to six months. Non-absorbable buried sutures have been known to surface years after placement, sometimes catching patients completely off guard when they feel a sharp point in a scar they had long since forgotten about.

What to Do When a Stitch Comes Through

If you can see a loop or end of thread sticking out of the skin and the surrounding area is not red, hot, or swollen, you can often manage it at home. Clean the area gently with mild soap and water or saline. If the thread is loose and clearly detached from deeper tissue, you can sometimes pull it out with clean tweezers, much like removing a splinter. It should slide out with minimal resistance. If it feels anchored or pulling on it causes pain, stop and leave it for your surgeon.

Resist the urge to dig around in the wound. An emerging stitch that is still partially embedded is best handled by a healthcare provider who can snip it cleanly and ensure nothing is left behind. Leaving a fragment can restart the inflammatory cycle and lead to another round of bumps and drainage.

Keep the area clean and covered with a simple bandage until the small opening closes, which usually takes a few days. If the spot around the stitch becomes increasingly red, warm, painful, or starts producing thick or foul-smelling discharge, see your doctor promptly. Those are signs of actual infection rather than simple extrusion, and they may require antibiotics.

One reassuring point: a spitting stitch does not usually mean something went wrong with your surgery. The deeper tissue repair is almost always intact by the time a buried stitch surfaces. The stitch has done its job holding things together during the critical healing window. Its exit is more of an afterthought than a complication, even if it does not feel that way at the time.

Barbed Sutures and the Extrusion Trade-Off

Barbed sutures are a newer category designed with tiny hooks along the thread, allowing them to grip tissue without needing knots. Surgeons use them for internal closures in cosmetic procedures like facelifts and body contouring because they distribute tension evenly along the wound and can speed up closure time. But the extrusion picture with barbed sutures is worth understanding.

A systematic review and meta-analysis of barbed sutures in cosmetic surgery found that while infection rates and delayed healing were comparable to traditional stitches, the risk of suture extrusion was roughly four times higher with barbed sutures.⁵ The same analysis found an increased risk of wound edges pulling apart. The problem was most pronounced with unidirectional barbed sutures, which have hooks running in only one direction, compared to bidirectional designs where hooks face both ways from the midpoint.

Suture extrusion has been flagged as one of the most common complications in certain cosmetic procedures using barbed sutures, particularly breast lifts.⁶ The barbs may irritate surrounding tissue more than a smooth thread, and the absence of a knot does not eliminate the foreign body response. If you are considering a cosmetic procedure and your surgeon mentions barbed sutures, it is reasonable to ask about extrusion rates for that specific operation and whether a traditional buried suture might be a better fit for your anatomy.

Patient Factors That Raise the Risk

Your own biology plays a role in whether buried stitches stay buried. People who tend to form thick, raised scars (hypertrophic scars or keloids) have a more aggressive wound-healing response, which can accelerate the rejection of foreign material. Smokers heal more slowly and often have a more disorganized inflammatory response, both of which can contribute to extrusion. Diabetes and conditions that impair blood flow to the skin similarly slow the absorption process for dissolvable stitches, giving the body more time to push the material outward before it fully dissolves.

Medications that suppress the immune system, like long-term corticosteroids, can paradoxically go either way. On one hand, reduced inflammation might mean less aggressive rejection of the suture. On the other, poor wound healing may leave the suture sitting in tissue that never fully incorporates it, and it drifts toward the surface by default. Nutritional status matters too. Adequate protein and vitamin C are essential for collagen production, and without them, the tissue around a buried stitch may not heal tightly enough to hold it in place.

Weight and body composition can affect things in a practical way. In areas with more subcutaneous fat, there is a thicker buffer between the buried stitch and the skin surface, so extrusion is less common. In very lean individuals or areas where the skin sits close to bone or tendon, the margin for error in stitch placement shrinks considerably.

How Surgeons Minimize Extrusion

Experienced surgeons have several strategies to reduce the chance of stitches surfacing. The most fundamental is knot placement. Burying the knot as deep as possible in the wound, ideally at the base of the dermis or in the subcutaneous fat, puts the maximum amount of tissue between the knot and the skin surface. Techniques like the buried vertical mattress suture and the double butterfly suture are specifically designed to anchor knots well below the skin.⁴

Material choice is another lever. For wounds under low tension in thin-skinned areas, surgeons may opt for faster-absorbing sutures that dissolve before the body has a chance to reject them. For high-tension closures, slower-absorbing monofilament sutures provide long-lasting support with a smoother surface that provokes less inflammation than braided alternatives.

Some surgeons use tissue adhesives or adhesive strips on the surface to take tension off the buried stitches, which reduces the mechanical forces that can push a knot upward. In cosmetic surgery, layered closure techniques that distribute tension across multiple tissue planes can also help. The goal is to minimize the load on any single buried stitch so it can dissolve in peace rather than being stressed and pushed toward the surface.

Suture Granulomas and When the Problem Goes Deeper

Sometimes the body’s response to a buried stitch goes beyond simple extrusion. A suture granuloma forms when the immune system walls off the foreign material in a dense ball of inflammatory tissue. These can appear as firm, tender lumps weeks to months after surgery, and on imaging they can mimic more concerning findings like tumor recurrence, which has led to unnecessary scares in patients being monitored after cancer surgery.

Suture granulomas are more common with braided and natural-fiber sutures like silk, which provoke a stronger and more prolonged immune response than synthetic monofilament materials. They can occur with absorbable sutures too, particularly if a fragment fails to dissolve completely. Treatment usually involves removing the offending material, either by pulling it out through a small incision or, in the case of deeper granulomas, minor surgical excision. Once the foreign material is gone, the inflammatory reaction resolves on its own.

The distinction between a spitting stitch and a granuloma matters practically. A spitting stitch is on its way out and usually resolves with minimal intervention. A granuloma is the body walling something off that it cannot expel, creating a persistent lump that may not resolve without help. If you have a firm bump along a scar line that is not improving after several weeks and does not have a visible thread poking through, mention it to your surgeon. It is a straightforward problem to fix, but it will not fix itself.

Oral Surgery and Internal Stitches in the Mouth

Internal stitches in the mouth deserve their own mention because the oral environment is uniquely challenging. The tissue is wet, constantly bathed in bacteria, and subject to movement from talking, chewing, and swallowing. Research has shown that suture materials placed in oral mucosa trigger more inflammatory reactions than sutures placed in tougher, keratinized gum tissue, and that braided sutures fare particularly poorly in the mouth compared to smooth monofilament options.²

If you have had wisdom teeth removed, jaw surgery, or dental implants placed, you may notice a stitch end working loose within the first week or two. In the mouth, this is especially common because the tissue heals quickly and the constant moisture can accelerate suture degradation. Most oral surgeons use absorbable sutures that are designed to fall out or dissolve within a week to ten days, so a loose end is often just the stitch reaching the end of its useful life rather than a true extrusion event. If a stitch comes loose in your mouth, it is generally safe to leave it alone or gently remove it with clean fingers if it is bothering you. Call your surgeon if you notice increasing pain, swelling, or a bad taste that suggests infection.