Prevention

The most important thing to consider in the management of keloid scar formation is prevention. Before surgical procedures are performed, a thorough history of abnormal scar formation or a family history of keloid scar formation should be obtained from the patient. If a history of keloid formation is obtained, all nonessential surgery should be avoided, especially at sites that are at high risk. In circumstances where surgery cannot be avoided, all attempts must be made to minimize skin tension and secondary infection. Antibiotics, meticulous sterile technique, and, rarely, perioperative steroid injections (mixed with lidocaine) are helpful in prevention as well.

Cryotherapy

Tissue destruction techniques used for treating keloids can incite further keloid formation. Cryotherapy, however, has been used with good results in 65% to 75% of cases. Both liquid nitrogen and nitrous oxide methods can be efficacious (see Chapter 14, Cryosurgery, Fig. 14-4). The more recent the keloid, the better the response to cryotherapy. A 10- to 15-second freeze with liquid nitrogen (−189° C) is usually required for keloids on most sites other than the mid-sternal region (small scars will take less time). Freezing for more than 10 to 15 seconds with liquid nitrogen can produce persistent post-treatment hypopigmentation. A 30- to 45-second freeze is usually adequate for most keloids when nitrous oxide (−89° C) is used. A better guide for any modality is to continue the freeze until 1 to 2 mm of normal tissue is involved and the complete thaw time is 1.5 to 2 minutes. During each treatment visit, the entire lesion must be treated with two to three freeze/thaw cycles.

After cryotherapy (see Chapter 14, Cryosurgery, Fig. 14-4), tissue edema will develop in 20 to 60 minutes. Within hours a significant bulla (blister) will appear. A rather copious serous discharge may follow. A moist environment (semiocclusive dressing) will aid healing. In southern and temperate climate areas, particularly during the summer months, occlusive therapy may prolong healing and increases the likelihood of secondary infection. Depending on the size of the lesion, five to eight treatments may be needed at 6-week intervals. Start conservatively and increase the freeze times if there are no untoward adverse effects.

Cryotherapy can also be used to soften hard keloids immediately before injection of steroids. Edema of the skin allows better dispersal of the steroid and minimizes its deposition into the subcutaneous or surrounding normal tissue. Cryotherapy before injection (liquid nitrogen spray for 3- to 5-second burst[s]) may also improve keloid regression, allows for lower injection pressures, and decreases the pain associated with injections. Allow 20 to 60 minutes for the edema to develop before proceeding with the injection.

Corticosteroid Injections

Once a scar is palpable, topical corticosteroids, even under occlusion (e.g., flurandrenolide [Cordran] tape), are rarely beneficial. Raised hypertrophic scars and keloids, however, may be softened and flattened by intralesional corticosteroid therapy. Corticosteroids represent effective monotherapy for some hypertrophic scars and small keloids, and they are frequently used as the initial therapy for large keloids.

Early, small, or narrow lesions are initially treated with intralesional injection every 4 to 6 weeks. Early keloids are softer and more responsive to injection than older, inactive lesions. Avoid injecting into surrounding normal skin to prevent perilesional subcutaneous atrophy and telangiectasis formation. When a lesion flattens to nearly the level of the skin surface, allow more time to pass before injecting again and decrease the concentration of the injections. Overaggressive therapy can lead to hypopigmentation and a depression resulting from the atrophy.

Injections are frequently performed with a 27- or 30-gauge needle on a Luer-Lok syringe. Locked syringes help to prevent needle disengagement when injecting under pressure. Consider using cryotherapy immediately beforehand (see the previous section) to ease injection and spread of the steroid.

Many steroid regimens have been developed, and there is considerable variation in guidelines and recommendations for dosages and drugs. No clear advantage has been shown for any one type of corticosteroid. Triamcinolone acetonide 10 mg/mL (Kenalog-10) is a popular choice because of its 4- to 6-week duration of action. Although undiluted steroid can be used for unresponsive or dense lesions, it is more prudent to dilute the triamcinolone 1 : 3 with physiologic saline or 1% lidocaine (single-dose vials) to create a 2.5 mg/mL solution. This dilute concentration limits postinjection hypopigmentation and atrophy. Injecting only lidocaine around the lesion using a 27- to 31-gauge needle before steroid injection improves patient comfort. Once the individual patient response is known, the concentration of triamcinolone acetonide can be increased to a dilution of 1 : 2 or 1 : 1 with lidocaine if necessary for future injections to increase the effect. If little effect is seen even without dilution, triamcinolone 40 mg/kg can be used and diluted as indicated. A common error is to be too aggressive. Go slowly to avoid the complication of atrophy. Hyaluronidase can be added to the solution to help disperse the steroid.

Administer the corticosteroid as the needle passes through the lesion. Keep the bevel of the needle pointed down. The scar may blanch temporarily with the injection. Try to keep the injection within the confines of the lesion to prevent side effects in the adjacent tissue. Firm lesions may limit the amount of medication that can be administered. The total amount will vary significantly depending on the size of the lesion. Keloids over 1 to 1.5 cm in diameter generally do not resolve as quickly or completely as smaller keloids. When the lesion is too dense to inject, consider treating with cryotherapy first, as previously discussed.

Another method of injecting steroids is to use the MadaJet Injector (see Pearl no. 8 in Appendix H, Pearls of Practice). The same concentration is used. The spring-loaded “gun” fires (dispenses) the solution, which is under pressure, into the lesion. No needles are involved, and there is less pain. Injections may again need to be repeated every 4 to 6 weeks to gain maximum benefit. The same dilutions are used.

Systemic effects from the corticosteroids are rare, but are possible with repeated injections of higher concentrations. Local effects include hypopigmentation, hyperpigmentation, perilesional atrophy, perilymphatic linear atrophy, and local telangiectasia. These effects often improve over time. This therapy is generally considered safe and effective.