Intralesional Cryosurgery: a Novel Treatment for Keloid Scars

K eloid scars—fibrous overgrowths that occur in sites of previous skin injury—are composed of excess collagen and often extend beyond the borders of the original wound (Figure 1). Keloids often develop soon after injury but can also occur up to several years following the initial traumatic insult. Common causes include surgical procedures, piercings, vaccinations, lacerations, and burn injuries.1 There is potential for all individuals (except albinos) to develop keloid scars; however, the greatest incidence is seen in patients of darker skin color. Keloids are most common in the second to third decades of life, and susceptibility decreases with age.2,3 Lesions are firm, pink to purple, and mildly tender. The most common anatomic sites to develop keloid scars include the anterior chest, shoulders, ear lobes, cheeks, and skin overlying joints. After development, keloid lesions continue to persist without spontaneous regression and have no malignant potential. Patients often complain of itchiness, pain, and abnormal sensitivity to touch. These symptoms, along with the contractures created from excessive scar formation, can be extremely uncomfortable for patients.2,3 The cause of keloid scar development is multifactorial, with a strong genetic component. Uncontrolled scar formation is due to aberrant wound healing following any injury to the deep dermis. Normal wound healing depends on the fine balance between extracellular matrix deposition and degradation. However, in keloid scars, there is overexpression of specific growth factors and inflammatory molecules that stimulate fibroblasts to increase collagen synthesis.1-3 Current therapies While multiple treatment modalities exist for treating keloid scars, no single method is proven to be widely effective. Steroid injections directly into keloids (intralesional) are the mainstay treatment method and are usually well tolerated by patients; however, approximately 50 percent of lesions recur after treatment.1,4 Alternatively, contact cryosurgery using liquid nitrogen to “freeze” the lesion is moderately effective, but patients may require up to 20 treatments.5-9 Often, these two methods (contact cryosurgery and intraleIntralesional Cryosurgery: a Novel Treatment for Keloid Scars