Cortisone injection for acne:
when a cyst is injected, the atrophy risk, and what else acne needs

What is a cortisone injection for acne?

A cystic or nodular acne lesion forms when a follicle ruptures deep in the dermis and the immune response walls off the spilled contents into a firm, tender lump. Because the inflammation sits millimetres below the surface, creams barely reach it, squeezing pushes it sideways, and it can be slow to settle on its own. The cystic and nodular acne page explains why these lesions hurt, persist and scar.

A cortisone injection, also called an intralesional corticosteroid injection or cortisone shot, goes straight to that inflammation. After examination, a doctor uses a fine needle to place a small volume of dilute corticosteroid, most often triamcinolone acetonide, into the centre of the lesion. The corticosteroid suppresses the inflammatory signals inside the nodule, with the aim of settling pain and swelling sooner than they would settle on their own; the lump can take longer to flatten fully and a mark may remain. DermNet lists acne cysts among the conditions treated this way, and acne guidelines from the American Academy of Dermatology include intralesional corticosteroid as an adjunct in their good practice statements.

The word adjunct matters. An injection acts on one lesion, in one place, at one time. It has no effect on the oil glands, follicles and inflammation that produced it, so it is used alongside acne treatment, never instead of it. A person with one occasional deep spot and a person with a steady stream of new cysts are having very different conversations, even if both ask for the same injection.

Which lesions are injected, and which are not: the lesion-by-lesion decision

The injection is considered for a lesion that is deep, firm, inflamed and tender, where calming it sooner is worth the small risk the injection carries. Typical examples are a large painful nodule on the face, a lesion that is distorting the skin, or one that has appeared before a wedding, an interview or a photograph. It is a decision made lesion by lesion, after looking at it and feeling it.

It is not the right tool in several situations:

• Small surface pimples and comedones. These settle with topical treatment and do not justify the atrophy risk.
• A soft, fluctuant lesion full of pus. This may need different care, and suspected infection is treated as infection first. DermNet advises against injecting into active skin infection.
• A site that has been injected before. Repeated corticosteroid at one spot raises the risk of a lasting dent or pale patch, so a lesion that keeps refilling in the same place is approached cautiously. It may have become a walled cavity that needs another approach.
• Lesions near the eye, pregnancy and known triamcinolone allergy. These are discussed individually, and an allergy rules it out.
• Many active cysts at once. Injecting each one treats the visible lesions while the disease continues; this is a signal that the medical treatment needs to change.

A lump that is not typical of acne, such as one that persists without inflammation, grows steadily or bleeds, is examined as a lump in its own right before anything is injected.

“An injection calms the cyst in front of you. It does nothing about the next one; that is what treating the acne is for.”

Dr Sin YongOn cortisone injections for acne

Cortisone injection for acne vs keloid steroid injection: the same medicine, a different job

The same corticosteroid is used for acne cysts and for keloids, which is why the two are sometimes confused. The target, the aim and the way the course is run are different.

The keloid steroid injection page explains the scar course in detail. A point the two share is that dose and depth decide most of the risk, which is why both are a doctor's procedure after assessment, not something offered across a counter. Acne itself can also lead to keloids on the jaw, chest and shoulders in people who are prone to them, and those scars are assessed separately from the active acne.

Can a cortisone shot leave a dent? Atrophy and other side effects

It can. The commonest delayed side effect of intralesional corticosteroid, as DermNet describes it, is lipoatrophy: the fat beneath the injection site thins and leaves a small depression in the skin. A pale patch where pigment is reduced is the other common one, and it shows more in darker skin, which describes most skin in Singapore. Fine visible vessels at the site can also appear. These changes are more likely when the concentration is stronger, the volume larger, the injection too shallow, or the same spot is injected repeatedly. They often improve with time, but not always, and a dent that persists is a form of scar.

Early effects are the expected ones of any injection: a sting, brief bleeding, a small bruise, and tenderness. Infection is uncommon. Because the amount placed is small and stays where it is put, effects elsewhere in the body are not expected at the doses used for a single lesion.

That risk profile explains how the injection is used: dilute, placed in the centre of the lesion rather than the surrounding skin, and kept for lesions where the benefit is clear. It is also why the injection is part of a plan to stop new cysts forming. Each cyst prevented is a cyst that never needs injecting.

When to contact the clinic

• Pain, heat or redness that increases instead of settling.
• A lesion that softens, fills with pus or begins to drain.
• A dent or pale patch you notice afterwards; it is reviewed rather than injected again.

What else is needed besides the injection?

The injection settles the lesion in front of you. What is aimed at preventing the next one is acne treatment matched to severity. For cystic and nodular acne that is usually medical: guidelines support oral treatment, including antibiotic courses in defined roles, hormonal therapy in women where a hormonal pattern is confirmed, and oral isotretinoin for severe or scarring acne, each requiring a doctor's assessment and prescription. The acne treatment page sets out those options, and isotretinoin and aesthetic treatment timing explains how procedures are planned around that medicine.

In adult women, a cyclical pattern of deep lesions along the jaw and chin raises the question of a hormonal contribution, covered on the hormonal acne page. In teenagers, early control matters because scarring from this age can last into adult life. Where acne is severe, unusual or not responding, Dr Sin Yong, an aesthetic physician, refers to dermatology.

Scars are treated once acne is under control, because resurfacing over active disease treats a moving target. Scar depth then decides the method: FSX for superficial scars, the S3 Resurfacing Lift for deeper ones, subcision first for tethered scars and TCA CROSS for ice-pick scars. The acne to scar pathway page explains how a deep lesion becomes a scar, and why the time spent controlling acne is time saved later.

What decides the plan

The plan depends on how many deep lesions are forming, where they are, the skin type, any earlier injections at the same sites, pregnancy or other medical factors, and which medical treatment is already in place. The fee follows the plan agreed after examination; how we quote explains what the written quote contains.