Intralesional Botulinum Toxin Type A Injection as a New Treatment Measure for Keloids

Abstract

Sir: Recently, we have used botulinum toxin type A to treat keloids by intralesional injection and have obtained good therapeutic results. In this article, we summarize our experience to communicate with others. This article is the first, to our knowledge, that reports the relationship between botulinum toxin type A injection and keloids. A keloid is a benign cutaneous tumor produced by uncontrolled synthesis and deposition of dermal collagen in predisposed individuals. Because of their characteristic aggressive and expansive nature, a variety of therapeutic agents have been used, without much success.1,2 Treatment of keloids still presents a major therapeutic dilemma. Thus, alternatives are needed. Because keloids are the result of excess accumulation of collagen that has been partly caused by increased tensile force during the course of traumatic cicatrization, decreasing tensile force in the local area of keloids becomes a logical strategy. Also, the efficacy and safety of botulinum toxin type A in inhibiting and preventing the tensile force caused by shrinking of skin and muscle have been established by long-term follow-up studies.3,4 Therefore, we conducted a prospective, uncontrolled study to evaluate the effects of botulinum toxin type A as a therapeutic agent in the treatment of keloids. Twelve patients (seven female and five male patients) with one or more keloids of varying size and duration who presented to the aesthetic surgery outpatient department in our hospital were randomly included in the study after written informed consent was obtained. In this study, a keloid was defined as an itchy, raised, persistent growth that had irregular margins. A detailed history—including duration; any predisposing factors such as trauma, infection, or any inflammatory skin disorder; any prior treatment implemented; evidence of any systemic disease; and family history—was obtained in all cases. In all patients, any prior treatment was discontinued at least 3 months before starting intralesional botulinum toxin type A therapy. Keloids of any duration were included in the study. Clinical evaluation regarding the number, size, and site of the lesions was also performed. Intralesional botulinum toxin type A in the concentration of 35 units/ml, with the total dose varying from 70 to 140 units per session, was given with a 24-gauge needle at 3-month intervals for a maximum of 9 months. Improvement was judged on the basis of a decrease in size and flattening of the lesion. Assessment of response to therapy was performed on the basis of patient satisfaction, photographic record, and observations of an independent observer at the beginning, at 1 and 3 months, and during follow-up at 1 year. The response was graded on a five-point scale as follows: no improvement; poor (up to 25 percent improvement); fair (26 to 50 percent improvement); good (51 to 75 percent improvement); and excellent (76 to 100 percent improvement). Improvement was assessed with respect to symptoms, size, height, and induration. Twelve patients in the group aged 16 to 45 years were included in the study. The number of keloids in each patient varied from one to three. The size of these lesions ranged from 1 to 6 cm and the duration ranged from 9 months to 25 years. The site of keloids was as follows: chest, shoulder, and earlobe. Family history of keloids was present in 33 percent of cases. The therapeutic outcome in these 12 patients was excellent in three patients, good in five patients, fair in four patients. None of the patients showed failure of therapy. The level of patient satisfaction with this form of treatment was very high. Regression from the periphery was noted in all of the patients besides flattening of the lesions. A significant decrease in size was observed in the patients. In the follow-up period of 1 year, no signs of reappearance of symptoms or the lesion were seen in any of the patients (Figs. 1 and 2).Fig. 1.: Before intralesional injection of botulinum toxin type A, the earlobe keloid grew rapidly; it was larger, and the color of the earlobe keloid was redder.Fig. 2.: After being treated by intralesional injection of botulinum toxin type A, the earlobe keloid disappeared. At the follow-up period at 1 year, no signs of reappearance of symptoms or the lesion were seen.Botulinum toxin type A has been developed for cosmetic and therapeutic use in plastic surgery. The objective of this study was to evaluate the role of botulinum toxin type A in the treatment of keloids. In this study, we have seen good results in all of the patients. Keloids of long duration and large size were seen to respond to botulinum toxin type A. According to our study, botulinum toxin type A may be an effective and safe treatment for keloids of all sizes and any duration. We believe that our study is significant in several ways: all patients were responsive to treatment and there were no serious adverse sequelae. Peripheral regression of lesions was noted, in addition to flattening in all cases, and there was no evidence of recurrence after 1 year. The reasons why administration of botulinum toxin type A results in improvement in keloids are unclear. We presume that there may be several related reasons. First, botulinum toxin type A prevents contraction of muscle and skin near keloid tissue, which decreases tensile force during the course of traumatic cicatrization. Second, some research has shown that botulinum toxin type A can suppress the secretomotor function and trophic effects of the cell. Botulinum toxin type A influences cellular apoptosis and cellular proliferation, which do well in keeping the balance of cellular dynamics.5,6 Because this study included a small number of cases and lacked the sustainment of the experimental data at the molecular or genetic level, we cannot ascertain the detailed mechanism between botulinum toxin type A and keloids. This needs further clinical observation and experimental research. We will next conduct the clinical investigation on a large scale to obtain a larger number of these cases and more data. On the basis of the clinical investigation, we plan to perform many experiments that may explain the detailed mechanism of botulinum toxin type A in the treatment of keloids. DISCLOSURE The authors have no financial interest in any of the products, devices, or drugs mentioned in this article. Xiao Zhibo, M.D., Ph.D. Zhang Miaobo, M.D. Department of Plastic Surgery 2nd Hospital Affiliated of Harbin Medical University Harbin City, Heilongjiang Province, China