Hypertrophic scars and keloids

A surgical scar, especially if it is on the face, should, if possible, be nearly invisible. Sometimes a scar becomes very visible indeed as the result of two processes: (1) hypertrophy and (2) keloid formation. Both these processes can follow surgery, tribal scarring, an injury, or almost any breach of the skin surface. Both cause large scars, and are identical histologically, but they behave differently.

Hypertrophic scars are common, wide, and raised. They are bright pink (in a light skin), are uniform, and do not extend beyond the edge of the original incision. They itch, and may be painful. They continue to thicken for 3 to 18 months, then become static, and finally resolve to become broad, soft, thin, and level with the surrounding skin; the whole process taking about three years.

Keloids are less common, but are not unusual in African patients. They are also wide and raised, but the new tissue grows beyond the original confines of the scar to form irregular mounds of collagen, which resemble benign tumours. Keloids may not start to form for many months after the original breach of the skin surface; they grow for a year or more, and then stop. There may be so many of them, and they may be so large, that they disfigure, deform, and disable the patient. Keloids are difficult to treat. If you excise one through normal skin and graft the gap, it is likely to recur round the edges of the graft, or in any gaps or splits in it.

Both a hypertophic and a keloid response are more likely if a wound is: (1) Infected. (2) Contaminated by foreign material[md]even monofilament sutures may promote them, but are less likely to do so than multifilaments. (3) Under tension. (4) In a young adult. (5) In a vascular part of the body (you will seldom find them on the legs or feet). (6) In a black-skinned patient.

THE PHYSIOLOGY OF KELOID FORMATION. Normally, there is a balance between the anabolic and catabolic stages of wound healing. As a wound heals, it goes through various stages. At about 3 or 4 weeks it is hyperaemic, and its strength is still only about a third that of normal skin. During the following 2 or 3 months, the hyperaemia subsides, and the scar becomes flatter and more pliable; at about 3 months it reaches its definitive state.

In an abnormal scar there is no equilibrium at 3 or 4 weeks, the anabolic phase continues, hyperaemia increases, more collagen is layed down, and the wound expands and becomes wider and raised. It may develop into a hypertrophic scar or a keloid. Both are stronger than a normal scar. Fig. 34-4 TWO ABDOMINAL SCARS. Both patients were operated on about 8 months previously. Patient A, has formed a keloid on her vertical scar. Patient B's transverse (Pfannensteil) incision in her skin crease has healed almost invisibly. Scars in skin creases are not under tension ]]and form less keloid. After Charles Bowesman, ''Surgery and Clinical Pathology in the Tropics''. E and S Livingstone, with kind permission.

THE KELOID RESPONSE THE DIFFERENTIAL DIAGNOSIS may be difficult early on.

Suggesting a hypertrophic scar[md]abnormal growth starting within weeks of the injury, growth restricted to the confines of the original scar, spontaneous regression in 6 months to 3 years, anywhere in the body, commoner than keloid in a white skin, very common in burns scars, itching is common and may be severe.

Suggesting a keloid[md]an onset delayed for months or years, invasion of the surrounding skin, growth stops in due course but there is no regression, localized to some parts of the body, not uncommon in black patients, uncommon in burn scars, very uncommon below the groin.

If diagnosis is difficult, remember that a keloid becomes increasingly raised, and extends beyond the confines of the original scar.

THE PREVENTION [s7]OF KELOIDS AND HYPERTROPHIC SCARS Minimize tension in the scar. Scars in the line of skin creases are under less tension than those across it. So plan incisions in skin creases where possible. If you have to cut across a crease, consider using a Z-plasty (57.11).

If possible, avoid scars in areas that are normally under tension: (1) In the neck especially. (2) In the coronal plane in the upper arm, especially its lateral side. (2) In the the upper back.

CAUTION ! Midline scars over the sternum and longitudinal incisions in the arm are particularly likely to develop keloids[md]they cross the skin's creases.

Maintain careful asepsis, minimize trauma when you operate, and control bleeding carefully at the end of the operation. Don't pull sutures too tight, and avoid mattress sutures.

POSTOPERATIVELY. [f41]If a patient is particularly likely to develop a hypetrophic scar or a keloid, as shown by his previous history, apply pressure to the scar for 9 to 12 months after the operation. Ideally, an elastic garment should be made to fit. This is unlikely to be practical, but you may be able to cut a piece of foam rubber to fit a smaller scar, and hold it in place with an elastic bandage. Tell him not to remove it except to wash. Unfortunately, both an elastic garment and an elastic bandage are are difficult to tolerate for long, especially in a hot climate.

TREATMENT [s7]FOR KELOIDS AND HYPERTROPHIC SCARS A HYPERTROPHIC SCAR. (1) If possible, leave it; often, it is not disfiguring. Reassure him that it will eventually regress naturally. Never operate during the active phase. If you decide to operate, do so during the mature phase, 3 years or more after the original wound. Then, excise the scar, and apply the preventive measures above. Considerable improvement is possible. (2) If he presents earlier than 3 years, before a scar is mature, apply pressure, as above.

A KELOID. Treatment is more successful if you start it early.

A developing keloid. Within a month or two of the injury: (1) Apply pressure. (2) Inject a suspension of hydrocortisone, about 2 ml at each site spread out subcutaneously. Or, better, use triamcinolone. Give 4 injections 3 weeks apart.

An established keloid. Steroids have no effect. Resist the request to operate if you can. The worse the keloid, the more likely it is to recur if you excise it. If you are pressed, excise smaller ones, but be sure to explain that they may recur and may even be worse.

If you operate, excise the abnormal tissue within the keloid, leaving a margin of keloid tissue all round. Keep your sutures within this margin also. If necessary, graft the bare area. You may be able to shave skin off the keloid and use this as a graft. All this is difficult; so is closing the wound tidily. Complete the incision and then inject steroid suspension into the scar. Postoperatively give him 4 more steroid injections at 3-weekly intervals. Apply a pressure bandage or an elastic garment for 9 months[md]if he will accept it!

Alternatively, follow the method of Bowesman in Fig. 34-5. Keloids are easier to remove from convex than from concave surfaces. A protruding keloid usually extends downwards like a saucer into the subcutaneous fat. Shave it off a little above the skin level, remaining within the keloid tissue and without entering the subcutaneous fat. Control bleeding, and apply a complete sheet of split skin extending beyond the margins of the keloid.

CAUTION ! (1) Try to avoid operating on established keloids. (2) Use a sharp knife. (3) Don't pull on the keloid as you excise it, or you may enter the subcutaneous tissue. Instead, if necessary, depress the surrounding tissues. (3) Don't use sutures.

Fig. 34-5 BOWESMAN'S ''SHAVING OFF' METHOD FOR KELOIDS. A, a keloid mass. B, the way to shave it off. C, the plane through which to remove it. D, a graft in place ready for dressing. After Charles Bowesman, ''Surgery and Clinical Pathology in the Tropics, Fig. 194. E and S Livingstone, with kind permission. Fig. 34-6 GRANULOMA PYOGENICUM. Excise or curette these lesions. Don't mistake them for a sarcoma! If there is any doubt about the diagnosis, send a piece for histology.