Keloids and hypertrophic scars are the two ways a healed wound can overdo it — producing more collagen than the injury needs, so the scar keeps growing past the boundaries of healing. The distinction between them is the first thing that matters. A hypertrophic scar stays within the original wound borders, usually develops within weeks of injury, and often flattens on its own over a year or two. A keloid grows beyond the wound margins into surrounding healthy skin, can appear months after a trivial injury (a pimple, an ear piercing, a vaccination), and almost never regresses spontaneously. That single difference — contained versus invasive — is why keloids are the harder problem and why cutting one out without a plan to stop it coming back is one of the most predictable mistakes in dermatology.
Both are far more common in skin of color. The incidence in Black and Hispanic populations (Fitzpatrick IV–VI) is estimated at 4.5–16%, versus roughly 0.09% in the lightest skin type, and darker-skinned individuals are up to 15 times more likely to form keloids than lighter-skinned individuals. Anyone writing about scarring in general terms without leading with skin of color is missing where the disease actually lives; for the broader framework on device and pigment safety across skin types, see our skin-of-color energy-device protocol. This article covers the evidence ladder for raised scars — what works, what is overrated, and why recurrence is the metric that matters most.
Why keloids behave the way they do
Keloidal scarring is a fibroblast problem: the cells that lay down collagen during healing stay switched on, overproducing type III collagen and responding excessively to TGF-β1, the signaling molecule that drives collagen formation. The result is a dense, disorganized collagen mass that is firm, often itchy or tender, and cosmetically prominent — frequently on the chest, shoulders, jawline, earlobes, and upper back, all high-tension or sebaceous areas where mechanical pull and inflammation conspire to keep the scar growing. Most of the treatments below work by either dampening that fibroblast activity (corticosteroids, 5-FU, bleomycin), choking off the scar's blood supply (pulsed-dye laser), or mechanically flattening it (pressure, cryotherapy). Prevention — avoiding elective skin injury in keloid-prone patients and closing real wounds under minimal tension — remains the single most effective intervention, which is an uncomfortable truth for a condition that often first appears after a piercing the patient now regrets.
Intralesional corticosteroids — the practical first line
Intralesional triamcinolone acetonide (TAC) is the workhorse first-line treatment for both keloids and hypertrophic scars. Injected directly into the scar, it reduces inflammation and promotes collagen degradation, flattening the lesion and relieving itch and tenderness. Published resolution rates range from 50% to 100%, with recurrence rates of 9–50% when used alone — which is the number to remember. International guidelines recommend triamcinolone at roughly 2.5–10 mg per site for scar management, repeated at monthly intervals; for monotherapy, 40 mg/mL is a common concentration, injected one to two times monthly until the scar flattens. It works best on smaller, younger, still-proliferative lesions.
The side effects are real and worth asking about: skin atrophy and thinning, telangiectasia (visible surface vessels), hypopigmentation — including a striking linear hypopigmentation that can be permanent and is especially visible in skin of color — and rarely necrosis or ulceration. These are local effects from the steroid escaping beyond the scar, and they are why concentration, volume, and injection technique matter. For patients who have already formed a keloid, intralesional steroid is the reasonable place to start; for patients who form them easily and are considering an elective procedure, it is worth discussing prophylactically with the provider beforehand.
Combination intralesional therapy — where the evidence is strongest
A consistent finding across recent trials and meta-analyses is that combination intralesional therapy beats any single agent. A 2025 meta-analysis of 18 randomized controlled trials found a mean response rate of about 82% and recurrence of about 17% across combination protocols, with combinations outperforming monotherapy in scar flattening, erythema reduction, and recurrence prevention. The most studied and effective pairing is TAC plus 5-fluorouracil (5-FU): low-dose 5-FU (roughly 1.5–5 mg/mL) combined with triamcinolone (2–10 mg/mL), injected at roughly four-week intervals for several months, inhibits the fibroblast proliferation driving the scar. 5-FU alone can be painful and cause ulceration, which is why it is nearly always paired with the steroid — both for synergy and for comfort.
For refractory keloids that have failed steroid, intralesional bleomycin is the next-tier agent, with evidence of superior response in resistant lesions. Other intralesional options studied include verapamil (a calcium-channel blocker that reduces collagen production — one trial showed it cut postsurgical recurrence by 90% at 18 months when combined with silicone sheeting) and botulinum toxin, thought to reduce scar tension by paralyzing adjacent muscle. The practical takeaway is not to memorize every agent but to know that a provider who offers only steroid to a stubborn, recurrent keloid is not using the full evidence base.
Cryotherapy, pressure, and silicone — the physical and home-care layer
Cryotherapy (freezing with liquid nitrogen, including intralesional cryo probes) effectively flattens keloids, especially smaller, acne-related lesions and ear keloids, and works particularly well combined with intralesional steroid. Its drawbacks are pain and a meaningful risk of permanent hypopigmentation — which, again, lands hardest in skin of color, where cryotherapy-induced depigmentation can be more persistent. Reported recurrence after intralesional cryotherapy ranges from 0% to 24% at 6–18 months.
Silicone gel sheeting is the evidence-backed home option. Sheets are applied over the scar for 12–24 hours a day for two to three months once the skin is closed; they soften and flatten scars and are also used for prevention. Silicone is non-invasive and low-risk, but it is time-intensive and patient-dependent. The FDA classifies scar-management silicone sheeting as a Class I device. Pressure garments (delivering sustained pressure, historically ~24 mmHg, worn for many months) are especially useful for hypertrophic scarring after burns, though the daily-wear commitment limits real-world adherence. Onion extract, vitamin E, and massaging a fresh, inflamed scar do not have supporting evidence — and aggressive massage of a still-inflamed hypertrophic scar may plausibly worsen it.
Laser — pulsed-dye for redness, fractional for texture
For the erythema (redness) and vascularity of a fresh raised scar, the 585/595 nm pulsed-dye laser (PDL) is the best-supported laser, targeting the scar's microvasculature to reduce redness, height, and pliability. A meta-analysis of 28 trials found an overall laser response rate of about 72% for keloid treatment and 68% for hypertrophic scars, with PDL and 532 nm lasers yielding the best responses; optimal PDL treatment intervals are roughly every 5–6 weeks. Typical PDL settings use a large spot size, short pulse duration, and fluences around 5–7.5 J/cm² — with lower fluence in skin of color to avoid post-inflammatory dyspigmentation from competing melanin absorption. We cover PDL and the related vascular lasers (Vbeam, KTP) in depth in our PDL/Vbeam vs. Excel V comparison.
For texture and remodeling of established scars, fractional CO₂ and Nd:YAG lasers are used, sometimes to assist drug delivery by creating microchannels that let intralesional steroid or 5-FU penetrate. The important caveat from the literature is that the level of evidence for laser as a keloid treatment is lower than for intralesional therapy, and laser is best understood as a complement to injection — not a replacement for it. Lasers can also re-trigger pigmentation in skin of color, the same PIH risk pattern discussed in our post-inflammatory hyperpigmentation guide.
Surgery and radiation — and why excision alone is a trap
Here is the single most important number in this article: the recurrence rate of keloids after surgical excision alone is 45–100%. Cutting a keloid out without an adjuvant plan is, for most patients, paying to re-trigger the very process that made the scar — and the recurrent keloid is often larger than the original. Surgery is still used, but only as part of a multimodal plan: excision followed immediately by postoperative radiation therapy (external-beam electron or high-dose-rate superficial brachytherapy), or excision followed by intralesional steroid injections, silicone sheeting, and/or pressure. With radiation as an adjuvant, recurrence drops substantially — a literature review of excision-verified keloids reported mean recurrence of about 10.5% for high-dose-rate brachytherapy and 22.2% for external radiation. Radiation is generally reserved for severe, recurrent, or large keloids because of long-term safety considerations, and it is delivered in collaboration with a radiation oncology team, not in a med spa. The point for a patient weighing "just cut it off": if a provider offers excision without an explicit adjuvant plan, that is a red flag, not a deal.
What it costs
Raised-scar treatment is often considered cosmetic and may not be covered by insurance, particularly for keloids that are asymptomatic; coverage is more likely when a keloid is symptomatic (pain, itching, functional impairment). Rough self-pay ranges vary widely by region and lesion: intralesional steroid injections typically run about $100–$300 per session with several sessions usually needed; cryotherapy around $100–$500; laser (PDL or fractional) about $300–$1,500 per course across multiple sessions; surgical excision roughly $1,000–$3,500; and postoperative radiation about $1,000–$2,000. Silicone sheets and gels are inexpensive over-the-counter products. The realistic budgeting question is staged — first-line injection cost, then the cost of escalation (combination agents, laser, or surgery-plus-radiation) if recurrence brings the scar back.
What to ask a dermatologist or plastic surgeon
- Is this a keloid or a hypertrophic scar? The answer changes the prognosis, the timeline, and the aggressiveness of treatment.
- What is your plan if it recurs? A credible answer names an adjuvant (steroid, 5-FU, radiation, PDL) — excision alone is not a plan.
- Will you use combination intralesional therapy, or steroid alone? Combination has the strongest evidence for stubborn lesions.
- How will you adjust laser or cryotherapy settings for my skin type? Lower fluence in skin of color is the right answer; ask about hypopigmentation and PIH risk specifically.
- What is the preventive plan for future procedures or piercings? Anyone who has formed one keloid is prone to more, and elective injury should be weighed accordingly.
- Is radiation appropriate in my case, and who delivers it? Radiation belongs with a radiation oncology team, reserved for severe or recurrent disease.
Keloids and hypertrophic scars are manageable but rarely curable on the first attempt. The patients who do best are the ones who treat recurrence as the real endpoint, who favor combination and multimodal therapy over a single dramatic intervention, who are honest about skin-of-color pigment risk before choosing laser or cryotherapy, and who work with a board-certified dermatologist or plastic surgeon rather than a clinic that promises to "just remove it."
Sources
- PMC — Keloids: A Review of Etiology, Prevention, and Treatment (TAC resolution 50–100%/recurrence 9–50%, intralesional cryotherapy 0–24%, radiation 10.5%/22.2% recurrence, PDL mechanism): https://pmc.ncbi.nlm.nih.gov/articles/PMC7158916
- PMC — A Comprehensive Review of Non-Surgical Treatments for Hypertrophic and Keloid Scars in Skin of Color (4.5–16% incidence, 15× darker-skin risk, laser combination data): https://pmc.ncbi.nlm.nih.gov/articles/PMC11193462
- Frontiers in Medicine — Efficacy and safety of glucocorticoid-based therapies for keloids: systematic review and meta-analysis (42 studies 2008–2025; the combination-therapy subgroup — TAC + 5-FU or laser-assisted TAC — pooled 18 RCTs and showed high-certainty superiority over monotherapy): https://pmc.ncbi.nlm.nih.gov/articles/PMC12832321
- PMC — Triamcinolone acetonide intralesional injection for keloid scars (agent overview, combination and excision+radiation options): https://pmc.ncbi.nlm.nih.gov/articles/PMC6063260
- UpToDate — Keloids and hypertrophic scars (TAC 2.5–10 mg/site, low-dose 5-FU 1.5–5 mg/mL, cryotherapy depigmentation): https://www.uptodate.com/contents/keloids-and-hypertrophic-scars
- American Academy of Family Physicians — Management of Keloids and Hypertrophic Scars (silicone sheeting 12–24 h/day, pressure for burns, verapamil 90% recurrence reduction, first-line TAC): https://www.aafp.org/pubs/afp/issues/2009/0801/p253.html
- Aetna Clinical Policy Bulletin — Hypertrophic Scars and Keloids (laser 72% keloid response, excision-alone recurrence 45–100%, FDA Class I silicone sheeting): https://www.aetna.com/cpb/medical/data/300_399/0389.html
- Cigna Coverage Criteria — Scar Revision (5-FU mechanism, intralesional agent evidence): https://static.cigna.com/assets/chcp/pdf/coveragePolicies/medical/mm_0328_coveragepositioncriteria_scar_revision.pdf
- CareCredit — Keloid Removal Cost and Treatment Options (cost ranges by modality, insurance medical-necessity note): https://www.carecredit.com/well-u/health-wellness/keloid-removal-cost-procedure-guide
