Key facts
- What is injected
- A corticosteroid, most often triamcinolone acetonide, placed within the keloid itself, not under or around it
- What it does
- Reduces inflammation, slows fibroblast collagen production and increases collagen breakdown, so the keloid softens and flattens
- How it is given
- A fine needle into dense scar tissue, in a course reviewed visit by visit; the interval is set at review
- Expected effects
- Pain during injection, tenderness afterwards; sometimes thinning or lightening of nearby skin
- Usually combined with
- Silicone, pressure, cryotherapy or laser, chosen by site and by how the keloid has responded
- Prescription status
- A prescription medicine given by a doctor after assessment; not available over the counter
How does a steroid injection flatten a keloid?
A steroid injection flattens a keloid by interrupting the process that keeps it growing. In keloid treatment the problem is not the scar that formed but the repair that never stopped: fibroblasts keep producing type I and type III collagen, inflammation persists in the deep dermis, and the lesion spreads past the original wound. Corticosteroids act on each part of that loop. They suppress the inflammatory signals that recruit fibroblasts, reduce the rate at which fibroblasts make collagen, increase the activity of the enzymes that break collagen down, and constrict the small vessels that feed the lesion.
The medicine most often used is triamcinolone acetonide, a prescription corticosteroid in a suspension that stays where it is placed rather than spreading through the body. It is injected into the body of the keloid itself, not into the normal skin beneath or around it, because that is where the overactive tissue sits and because steroid in normal skin causes the thinning described below. Over a course, the keloid typically becomes softer, flatter and less itchy; how far it flattens depends on its size, age, site and the person's own tendency, and is discussed at assessment.
Who tends to form keloids, and who is offered injections?
Keloids form in people whose skin answers injury with prolonged, excessive collagen production, a tendency that is largely inherited and is substantially more common in Chinese, Malay, Indian and African skin than in white European skin. Piercings, acne, surgical wounds, burns, BCG vaccination and sometimes trivial scratches can trigger one, especially on high-tension skin such as the chest, shoulders, jawline and earlobes. The keloids and hypertrophic scars guide explains how a keloid is told apart from a hypertrophic scar, which stays within the wound and often settles on its own.
Steroid injections are offered for a confirmed keloid that is raised, itchy, tender or growing, and for hypertrophic scars that have not flattened with silicone and pressure. They are deferred when the skin over the scar is infected or broken, reviewed carefully in pregnancy and breastfeeding, and discussed before use in people with diabetes, glaucoma or other conditions that corticosteroids can affect. A lump that appeared without any injury, grows quickly, bleeds or ulcerates is examined, and sometimes biopsied, before it is treated as a keloid.
“Cutting a keloid without an adjuvant plan is offering it a fresh wound — the recurrence isn't bad luck, it's the biology you invited.”
Dr Sin YongOn why excision alone is avoided
What happens during a course, step by step?
The first visit is an examination: Dr Sin Yong confirms that the lesion is a keloid, records its size, firmness and symptoms, asks about family history and earlier treatment, and sets out a written plan with the combination of treatments proposed and how they will be staged. On a treatment day the area is cleaned, a numbing cream or cold may be applied, and the medicine is injected through a fine needle at several points across the keloid until the tissue blanches slightly. Dense keloids resist the needle, so the injection is felt as pressure and stinging; comfort measures are discussed beforehand.
The keloid is then reviewed, and the next injection is timed by what the review shows rather than by a fixed schedule. Softening is usually the first change, then flattening. The concentration and the amount placed are adjusted to the response and to any thinning of the surrounding skin. Where a keloid has stopped responding, the plan changes rather than the dose simply rising: combining the steroid with 5-fluorouracil, adding cryotherapy or laser, or referring for excision with adjuvant treatment are the usual directions, each with its own discussion.
How a keloid steroid injection compares with the measures used alongside it| Measure | What it does | What it cannot do | Where it fits |
|---|
| Intralesional corticosteroid | Calms inflammation, slows collagen production, softens and flattens | Remove the tendency to form keloids or prevent recurrence alone | First-line for most keloids, in a reviewed course |
| Steroid with 5-fluorouracil | Adds an agent that slows fibroblast growth in resistant keloids | Replace assessment of why the keloid stopped responding | Keloids that plateau on steroid alone; discussed case by case |
| Silicone gel or sheeting | Hydrates and covers the scar to help hold flattening | Flatten a large established keloid by itself | Daily use between visits and after treatment |
| Pressure | Sustained compression of the treated scar, for example a clip earring | Work where even pressure cannot be applied | Earlobes in particular, after injections |
| Laser | Reduces redness and improves surface texture | Flatten bulk on its own | Adjunct for red or textured keloids |
| Excision with adjuvant treatment | Removes bulk, followed by injections or other adjuvants | Be relied on alone; recurrence after solo excision is frequent | Selected large keloids, referred to a plastic surgery specialist |
What are the side effects, and when should you call?
The common effects are pain during the injection, tenderness and a little swelling afterwards, and small bruises. The effects that matter over a course come from steroid reaching tissue that did not need it: thinning of the skin around the keloid, a dent where fat beneath has shrunk, lightening of the skin, which is more visible in darker skin, and fine visible vessels. These are the reason the medicine is placed within the keloid, the dose is kept to what the lesion needs, and the surrounding skin is checked at each visit. With large or repeated doses the medicine can be absorbed into the body, and changes to the menstrual cycle, acne or raised blood sugar in people with diabetes are discussed before a course begins.
Call the clinic for increasing pain, spreading redness, pus or fever, an open wound in the scar, rapid growth of the lesion, or marked thinning or colour change of the nearby skin. The complication care page explains what to do if something feels wrong after a treatment, wherever it was done.
What is combined with injections, and what should you avoid?
Injections are seldom the whole plan. Silicone gel or sheeting worn daily hydrates and covers the scar and helps hold flattening between visits; pressure, for example a clip earring after an earlobe keloid is treated, applies the sustained compression that keloid-prone skin needs; cryotherapy freezes bulk in small lesions; and laser is directed at the redness and surface texture rather than the bulk. Surgical excision is referred to a plastic surgery specialist for selected large keloids that have not responded, always with adjuvant treatment such as steroid injections afterwards, because excision on its own frequently recurs larger.
Avoid having a keloid cut out without an adjuvant plan, tying it off with thread, applying acids, vinegar or unregulated bleaching creams, and squeezing or picking the skin around it, since each adds inflammation to tissue that answers inflammation with growth. Avoid new piercings or tattoos on high-risk skin while a keloid is being treated, and declare a keloid tendency before any procedure that breaks the skin. Fees are set out in writing after assessment, as the fee page explains, and they depend on the size and number of lesions, the site and the modalities the plan combines.
