Keloid and Hypertrophic Scars

Keloid and Hypertrophic Scars: Keloid formation is one of the mysteries of human pathology. Especially mysterious is why similar injuries produce a keloid in one person and not in another. Why, in the same person, will an injury to the skin produce a keloid in one area of the body and not in another? Generally, a hypertrophic scar is a thickened scar at the site of an injury to the skin. This scar does not go beyond the border of the cut or surgical wound, whereas a keloid scar extends beyond the border. A keloid means a “crab-like” scar. A hypertrophic scar will flatten out spontaneously by one year. If the scar is still thickened after one year it will not usually flatten by itself. Keloid scars will often increase in size for many years.

The anterior chest area and outer shoulders are the most common sites for keloids but they can occur almost anywhere. The first evidence of an abnormal scar formation usually begins between the third and fifth week of healing. The growth of excessive scar tissue is rapid for six weeks and may continue at a slower rate for months to years.

KELOID SCARS - MANAGEMENT

DEFINITION: Hypertrophic scars remain within the confines of the original wound and usually regress spontaneously. Keloids extend beyond the wound in all dimensions and expand with time instead of regressing.

EPIDEMIOLOGY: Keloids are more common in darker pigmented races. Keloids may occur at any age but the average age of onset is 22 years for both men and women.

ETIOLOGY: Factors that play a major role in keloid development are:

• Genetic Predisposition
• Type of skin injury
• Location (Deltoid, anterior chest, ear lobes)
• Pregnancy

CLINICAL FEATURES

Hypertrophic Scars

• Develop soon after injury
• Regress with time (1 year)
• Limited boundary
• Size corresponds to injury

Keloids

• May take many months
• Do not regress with time
• Grow beyond boundary
• Minor wound may produce large keloid
• Area of high incidence are shoulders, anterior chest, ear lobes
• Rare on eyelids or genitalia

MANAGEMENT:

A) TOPICAL

• Retinoids - Vitamin A acid
• Steroids with occlusion
• Silicone Gels (Fresh scars, less than 3 months)

B) INTRALESIONAL STEROIDS

• Kenalog 10-40 mg/cc normal saline, not Xylocaine
• mixed with hyaluronidase (Wydase)
• Ligmaject technique
• Intradermal, Emla
• every 5-7 weeks

C) INTRALESIONAL 5 FU (R. Fitzpatrick)

• mix with Kenalog
• 3 times per week
• Maximum 100 mg per session
• Best for hypertrophic scars and fresh keloids

D) CRYOSURGERY

• liquid nitrogen jet spray
• use cones

E) IRRADIATION

F) PRESSURE

• Scars older than 6-12 months respond poorly
• Pressure garments, devices are uncomfortable and must be worn day and night for 9-12 months
• Effective pressure (25-40 mm Hg) not readily achieved in many anatomical areas

G) SURGERY

• simple excision
• W-Plasty best for faces
• Z-Plasty not usually for faces (except for eyelids)
• when combined with intralesional steroids leave sutures in 3-5 days longer

H) LASERS

1) High Energy pulsed CO₂ lasers

• Focused - excision mode
• Vaporization - combined with Erbium Yag
• Faces and ears only

2) Erbium Yag (used in combination with high energy pulsed CO₂ laser)

3) Dualmode lasers

• Er:YAG and CO₂ Laser (DermaK, by ESC)
• Pulsed Er:YAG Laser (Sequential ablation and coagulation/ Contour, by Sciton)
• CO₃ Laser by Cynosure variable pulse Er:YAG laser single pulse from 500 msec to 10 msec.

4) Vascular Lasers

• P.D.L.
• Versapulse
• Vasculight

I) OTHER TREATMENT MODALITIES

• Gamma - interferon
• Interferon Alfa - 2b
• Madecassol
• Colchicine
• Calcium Antagonists
• Pentoxifylline (Trental)
• Vitamin E topical / oral
• Coblation (Visage)

GOAL IN MANAGING KELOIDS

• Restoration of function
• Relief of Symptoms
• Enhanced Cosmetics
• Prevention of Recurrence