Steroid (Kenalog) injections for keloids: number of sessions, intervals and side effects

What is a Kenalog injection, and why is it injected into a keloid?

Kenalog is a brand name for triamcinolone acetonide, a steroid injected directly into the keloid tissue to calm the inflammation and the excess collagen production that make it grow. The American Academy of Dermatology notes that steroid injections shrink keloids, soften them and ease itching and pain, and that in most cases several injections are needed¹.

Steroid injections into a scar are also used for a hypertrophic scar, but for keloids they are the most common and longest-established treatment, and are almost always given as a series rather than a single injection.

The steroid is injected into the keloid itself, not into the healthy skin around it. This is the difference between a treatment that flattens the scar and a dent in the surrounding skin: precise injection into the hard tissue is a central part of the technique³. For all types of scar injections, including 5-FU and botulinum toxin, see scar injections.

How many injections does a keloid need?

There is no fixed number in advance. Most people need a series of several injections, and treatment continues as long as the keloid keeps flattening and there are no side effects that require stopping. A review of triamcinolone for keloids describes series of repeated injections, with the number depending on the keloid's size, its location and the response³.

What affects the number of injections:

• Size and thickness: a small, relatively flat keloid usually responds faster than a thick, large one.
• Age of the keloid: a new, active keloid usually responds better than an old, very hard one.
• Location: on the chest and shoulders, where the skin is constantly stretched, keloids tend to be more stubborn. See keloids on the chest and shoulders.
• Response to the previous injection: this is the most important factor, and it is assessed at every visit³⁵.

How often are the injections given?

The usual interval is a few weeks between injections. In a UK hospital patient leaflet the interval is usually 6 to 8 weeks, and the effect is described as cumulative. This is the time the tissue needs to respond, and it also allows checking whether side effects have started before injecting again⁴.

Injecting too early, or too large an amount each time, increases the risk of a dent and lightening of the skin. So as the keloid flattens, the amount is usually reduced, and the intervals can be lengthened³.

How do you know the treatment is working?

The first signs are usually softening of the keloid and relief of itching and pain, followed by gradual flattening of the keloid. The change in color is slower, and sometimes redness or darkening remains long after the keloid is already flat¹².

The British Association of Dermatologists stresses that the goal is to improve the keloid and the symptoms, and that even after good treatment it can come back⁸.

Side effects of Kenalog injections in a keloid

Most side effects are local: a dent in the skin or the fat beneath it, lightening of the skin color, small blood vessels (telangiectasias) and sometimes pain during the injection. DermNet lists the dent and the color change as the recognized side effects of steroid injections into a scar².

• Dent (atrophy): usually appears two to three months after the injection, and tends to improve slowly over one to two years⁷. Full information on the page skin dent after a steroid injection.
• Lightening of color: more noticeable in darker skin, and usually fades within weeks to months⁷.
• Small blood vessels on the surface of the scar or at its edges.
• Pain: the keloid is hard, and injecting into it is unpleasant. Cooling or a numbing cream before treatment helps some people⁴.
• Infection: rare.

Effects on the whole body are uncommon with keloid injections, because the amount is small. If you have diabetes, mention it before the injection and monitor your blood sugar in the days afterward. Steroids are not injected into scars during pregnancy⁵.

What is done when the keloid does not respond to the injections?

When the keloid responds only partially or stops improving, the steroid dose is not simply increased; another treatment is added, mainly 5-FU in the same injection. A 2026 network meta-analysis that included 24 controlled trials found that combining triamcinolone with 5-FU gave the best balance between treatment response and reduced recurrence⁶.

Ogawa's updated algorithm proposes a stepwise approach: start with the simple treatment and add combinations according to the response, including cryotherapy, vascular laser, and for a large, resistant keloid also surgery with radiation⁵. Details on the combination on the page 5-FU and Kenalog for keloids.

How is recurrence prevented after a series of injections?

After the keloid has flattened, follow-up, silicone and avoiding irritation continue, because a keloid can come back even after a good response. The American Academy of Dermatology notes that keloids often come back, and that home treatment such as silicone can be added to reduce the risk¹.

• Silicone as a sheet or gel, every day, for months.
• Pressure, mainly on the ear, with a pressure earring after treatment.
• A follow-up visit every few months in the first one to two years, to catch recurrence early and inject again while it is small.
• Avoiding new injuries in the area, including piercings and tattoos, if you are prone to keloids.

When should you come in for an examination?

It is worth coming in for an examination when a scar starts to grow beyond the borders of the wound, when it itches or hurts, or when a treated keloid starts to come back. Treating a small, new keloid is simpler than treating a large, old one¹.

A lesion that grows very fast, bleeds, opens up, or does not look like a typical keloid needs evaluation and sometimes a biopsy, because some rare skin tumors look like a scar at first². On the difference between a keloid and an ordinary raised scar, see hypertrophic scar.

How is it done at Dr. Dana Buchbut's clinic?

Dr. Dana Buchbut, physician (M.D.), examines the scar and gives the injections herself: she distinguishes between a keloid and a hypertrophic scar, assesses size, location and age, and builds a plan that assumes from the start that the keloid can come back.

The injections are given into the keloid tissue, in an amount set according to its size and the response since the previous visit, and the surrounding skin is checked at every visit. When the keloid responds only partially, Dr. Dana considers combining 5-FU with the steroid, after explaining that this is an off-label use. Between injections she gives instructions on silicone and pressure, and after the series is completed a follow-up visit is scheduled. A lesion that looks unusual is referred for evaluation first. General information on keloids on the page keloid scar.

The information on this page is general educational information only and is not a substitute for an examination, diagnosis or personal medical advice. A decision about treatment is made only after an examination.