A keloid is an overgrowth of dense scar tissue that extends beyond an original wound. This happens when the body produces too much collagen during healing, creating a raised, firm scar that may itch or be painful. Injections are a primary non-surgical treatment used to reduce the size and improve the texture of keloids.
Types of Injections for Keloids
The most common substance used in injections for keloids is a corticosteroid called triamcinolone acetonide (TAC). Corticosteroids counteract the biological processes that create keloids. They suppress inflammation, constrict blood vessels, and inhibit the activity of fibroblasts and keratinocytes, the cells that produce excessive collagen.
Beyond corticosteroids, other injectable substances are available, often used for keloids that are resistant to steroid treatment. One such agent is 5-fluorouracil (5-FU), a chemotherapy drug that inhibits DNA and RNA synthesis. This action slows the proliferation of the fibroblast cells that drive keloid growth. Due to its potency, 5-FU is frequently combined with a small amount of triamcinolone to manage side effects like pain and inflammation.
Another option is bleomycin, an antibiotic with antitumor properties also used in cancer treatment. Its mechanism involves causing DNA strand breaks, which induces programmed cell death in the fibroblasts. Like 5-FU, bleomycin aims to halt growth by reducing the number of collagen-producing cells. The choice between these agents depends on the keloid’s characteristics and a patient’s response to previous treatments.
The Injection Treatment Process
Treatment begins with an initial consultation, where a dermatologist assesses the keloid’s size, thickness, and location. During this visit, the practitioner discusses the most appropriate treatment plan, including the type of injection. This evaluation establishes a baseline and sets realistic expectations.
The injection procedure is quick and performed in an outpatient setting. The keloid and surrounding skin are cleansed with an antiseptic to prevent infection. A fine-gauge needle is then used to inject the medication directly into the dense scar tissue. Patients may feel a stinging or burning sensation, though this discomfort is brief.
Managing keloids with injections is not a single-session solution but requires a series of treatments. Injections are scheduled every four to six weeks, and the total number of sessions varies depending on the keloid’s response. Consistent follow-up is necessary to monitor progress and adjust the treatment plan as needed.
Expected Outcomes and Side Effects
The primary goals of injection therapy are to flatten the keloid, soften its hard texture, and alleviate symptoms like pain and itchiness. Successful treatment can lead to a significant reduction in the scar’s height, with some studies showing a flattening of 50% to 80%. While complete removal is not always achievable, the improvements can be substantial, though keloids may recur after treatment.
Potential side effects are localized to the treatment area. The most common issue is pain at the injection site, which usually subsides shortly after the procedure. Skin atrophy, a thinning or depression of the skin, can also occur if the corticosteroid affects the healthy tissue surrounding the keloid.
Other possible side effects include pigmentary changes. Hypopigmentation (lightening of the skin) and hyperpigmentation (darkening of the skin) are known risks, particularly for individuals with darker skin tones. These changes may resolve over several months or be long-lasting. The appearance of tiny blood vessels, known as telangiectasias, is another possible outcome.
Combining Injections with Other Therapies
For large keloids or those that do not respond to injections alone, combining treatments is often more effective at improving outcomes. This is especially true after surgical removal, a procedure with a high recurrence rate when performed alone. Administering steroid injections into the site following excision helps suppress the healing response that could trigger a new keloid.
Cryotherapy, a procedure that freezes scar tissue with liquid nitrogen, also pairs well with injections. Freezing the keloid softens the dense tissue, which allows the injected medication to penetrate more effectively. This combined approach can enhance the overall flattening of the scar.
Silicone gel sheets are a non-invasive option used with an injection regimen. These sheets are applied to the keloid to hydrate the scar tissue and apply light pressure. When used with corticosteroid injections, silicone sheets can help maintain progress between sessions and contribute to a better final result.