Pimple that turned into a keloid: why it happens and how to treat it

A pimple that turned into a keloid is a frequent complaint, especially among adolescents and young adults with inflammatory acne on the chest, shoulders, and jawline. What seemed like a common pimple evolves into a raised, red, and itchy scar — the keloid.

Why does this happen?

Inflammatory pimples (papulopustular and cystic) cause follicle wall rupture and deep dermal inflammation. In some people, the healing of this lesion produces excess collagen, creating a scar that does not stop growing — the keloid.

Three factors combine:

• Genetic predisposition to keloids
• Intense inflammation from acne
• Area of tension (chest, shoulders, back, jawline)

Who is at higher risk?

• Personal or family history of keloids
• Darker skin (phototypes IV, V, and VI)
• Adolescents and adults up to 30 years old
• Nodulocystic acne (large, deep, painful pimples)
• Habit of squeezing pimples

How to prevent

1. Treat active acne with a dermatologist — benzoyl peroxide, acids, topical/oral antibiotics, or isotretinoin when indicated.
2. Do not squeeze. Squeezing increases inflammation and the risk of keloids.
3. Daily sun protection — sun worsens scars and stimulates hyperpigmentation.
4. Preventative silicone for people with a history of keloids, as soon as the lesion heals.
5. Avoid friction from clothes, backpacks, and necklaces over predisposed areas.

Treatments for already formed keloids

First line: corticosteroid injection

Intralesional Triamcinolone, in monthly sessions for 3 to 6 times. Reduces volume, redness, and itching in most patients.

Silicone

Silicone sheets or gels used continuously complement the injection and reduce recurrence.

Laser

Vascular laser (PDL) for the red component; ablative fractional laser for texture and drug delivery (potentiates the corticosteroid).

Cryotherapy

Controlled freezing for smaller keloids; effective alone or combined with injection.

Surgery + radiotherapy

Reserved for large, painful, or refractory keloids. Surgery alone has a high recurrence rate — always combined with low-dose radiotherapy within the first 24 to 48 hours post-operatively, and silicone/corticosteroid afterwards.

What NOT to do

• Squeeze pimples, especially on the chest, shoulders, and jawline
• Aggressive exfoliants on formed keloids
• Homemade ointments or unprescribed healing creams
• Tattoo over keloids — risk of additional stimulation
• Sun exposure without protection

When to seek evaluation

• Pimple scar that continues to grow after 1 month
• Itching or pain in the scar
• Red, raised, hard scar
• Multiple lesions on the chest, shoulders, or jawline
• Personal or family history of keloids

Frequently Asked Questions

Why does a pimple turn into a keloid?

Intense acne inflammation (especially cystic) deeply damages the skin. In predisposed individuals and in areas of tension (chest, shoulders, jawline, back), healing produces excess collagen and forms a keloid.

Where do acne keloids appear most often?

The chest (sternum), shoulders, upper back, and jawline are classic regions — all with high skin tension and exposure to continuous movement.

Can a small pimple also turn into a keloid?

Yes. In predisposed individuals, even small lesions can evolve into keloids, especially if they are squeezed, infected, or exposed to the sun. Not squeezing and treating active acne is the primary prevention.

Is it possible to prevent acne keloids?

Yes: treat active acne appropriately, avoid squeezing, protect from the sun, and for people with a history of keloids, start preventative silicone as soon as the inflammatory lesion heals.

What is the most effective treatment?

Monthly corticosteroid (Triamcinolone) injection is the first line. It can be combined with silicone, laser, cryotherapy, and, in selected cases, surgery with radiotherapy. The result largely depends on the size and duration of the keloid.