Key facts
- Why here
- The sternum, shoulders and upper back are stretched with every breath and arm movement, and tension drives keloid growth
- Usual triggers
- Acne and folliculitis, BCG vaccination on the upper arm, surgical scars such as sternotomy, burns and friction
- Typical shape
- Spreading laterally along the lines of tension: crab-claw, butterfly or dumbbell forms over the sternum and deltoid
- Symptoms
- Itch, tenderness, a pulling or burning feeling, worse with heat, sweat and tight straps
- Approach
- Intralesional corticosteroid as the backbone, with silicone, pressure where it can be applied, and laser for redness
- Surgery
- Referred to a plastic surgery specialist only for selected lesions, with tension-reducing closure and adjuvant treatment
Why do keloids favour the chest and shoulders?
Keloids favour the chest and shoulders because the skin there is under constant mechanical tension, and tension is one of the strongest drivers of keloid growth. The sternum is stretched with every breath and with the movement of the pectoral muscles; the deltoid skin is pulled with every lift of the arm; the upper back moves with the shoulder blades. Keloid treatment at these sites therefore has to work against a force that never switches off, which is one reason they behave differently from a keloid on a protected site. The keloids and hypertrophic scars guide covers the shared biology; this page is about what the location changes.
The triggers are also different. On the face and earlobe a keloid usually follows a single wound such as a piercing. On the chest and shoulders the commonest triggers are acne and folliculitis, which produce many small inflamed wounds across tension-bearing skin, so several keloids can arise together and merge. BCG vaccination on the upper arm leaves a scar on exactly the skin the deltoid stretches. Surgical scars that cross the sternum, such as after heart surgery, and scars from burns or shoulder surgery sit across the lines of tension rather than along them.
How do chest and shoulder keloids look and feel?
Chest keloids tend to spread sideways along the lines of tension, so a lesion that began at a single acne spot over the sternum can extend into a butterfly or crab-claw shape with extensions running outward toward the collarbones. Shoulder keloids are often rounded or dumbbell-shaped nodules over the deltoid, firm, shiny and darker or pinker than the surrounding skin. Both are commonly multiple. Because they sit on skin that moves, they are more symptomatic than most keloids: itch, tenderness, a burning or pulling sensation, and discomfort under bra straps, backpacks and seat belts are the usual complaints, and heat and sweat make them worse.
The examination checks the border, because a raised scar that has stayed within a surgical line or an acne spot is more likely to be hypertrophic and may settle with silicone and pressure alone. It also checks for active acne or folliculitis around the lesions, since new inflamed spots keep feeding new keloids, and for signs that call for a biopsy, such as rapid growth, bleeding or ulceration without an obvious trigger.
“A keloid grows past the edge of the wound that caused it. A hypertrophic scar does not. That single boundary decides almost everything that follows.”
Dr Sin YongOn distinguishing the two
What does treatment involve at these sites?
Treatment at these sites rests on intralesional corticosteroid injections, given into the keloid in a reviewed course, and the chest and shoulder are where injections most often need combining with something else. Active acne is brought under control alongside, because a keloid plan over skin that is still breaking out is a plan with a hole in it, and the acne treatment page sets out how that is done. Laser is added for redness and texture, and cryotherapy for small bulky nodules. Where the keloid has stopped responding, 5-fluorouracil may be combined with the steroid after a separate discussion.
Silicone and pressure are harder to apply here than on an earlobe. Silicone sheets slip on a moving, sweating chest, so gel formulations and consistent daily use matter more than the product. Pressure garments can be used over the shoulder and upper back; on the sternum they are less practical. Surgery is referred to a plastic surgery specialist only for selected lesions, and when it is considered the plan includes a closure designed to reduce tension across the scar and adjuvant treatment immediately afterwards, because excision alone at a high-tension site is the setting in which recurrence is most expected. Fees depend on the number and size of lesions and the combination of modalities, and are quoted in writing after assessment.
How site changes the picture: chest and shoulder keloids compared with other sites| Feature | Chest and shoulder | Earlobe | Jawline |
|---|
| Main driver | Constant tension from breathing, arm movement and posture | A single piercing tract in loose fibrofatty tissue | Tension from jaw movement plus acne |
| Usual trigger | Acne, folliculitis, BCG, sternotomy and other surgery, burns | Piercing | Acne and shaving injury |
| Typical shape | Spreads sideways: crab-claw, butterfly or dumbbell forms, often multiple | Rounded nodule, sometimes front and back of the lobe | Firm nodules along the jaw |
| Symptoms | Itch, burning and pulling, worse with heat, sweat and straps | Usually less symptomatic | Tenderness, irritation with shaving |
| Pressure and silicone | Harder to keep in place on a moving, sweating chest | Clip earrings apply even pressure well | Possible with silicone gel |
| Surgery | Reserved; tension-reducing closure and adjuvant treatment are essential | Considered more often, always with adjuvant treatment | Reserved |
What makes these keloids worse, and what should you avoid?
Anything that adds tension, friction or inflammation makes a chest or shoulder keloid worse. Avoid squeezing or picking acne and folliculitis on the chest, back and shoulders; each squeezed spot is a new wound in keloid-forming skin. Avoid tight straps that rub across a keloid, and pad a seat belt or bag strap that crosses one. Chest tattoos, piercings through the skin of the chest and elective procedures on the upper trunk deserve real hesitation in anyone who has formed a keloid there.
Avoid excision without an adjuvant plan, and avoid home remedies such as thread ligation, acids or vinegar, which add inflammation to tissue that answers inflammation with growth. Heat, saunas and vigorous exercise are not forbidden, but a keloid that flares with heat and sweat is a reason to keep the skin cool and dry where possible. Call the clinic for increasing pain, spreading redness, pus or fever, an open wound in the scar, or rapid growth; the complication care page explains what to do if something feels wrong after a treatment.
When should a chest or shoulder keloid be assessed?
Assessment is worthwhile when a raised scar on the chest, shoulder or upper back is growing beyond the spot or line it started from, when it itches, aches or catches on clothing, when acne on the trunk keeps leaving firm lumps, or before any planned surgery on the chest in someone who has formed a keloid before, because prevention can be planned into the wound care. A lump with no clear trigger, or one that bleeds or ulcerates, is examined before it is labelled a keloid.
At the consultation Dr Sin Yong examines the lesions and the skin around them, confirms the diagnosis, and sets out a staged plan in writing, including what is realistic for lesions of that size and site and how recurrence is guarded against. The consultation process page describes what to expect and what to bring, including photographs of how the scar has changed.
