Dermatologic Surgery最新文献

Background: Botulinum toxin A (BoNT-A) is widely used in treating dystonia and spasticity to managing chronic migraine and cosmetic applications. However, its immunogenic potential presents challenges, such as the development of neutralizing antibodies that lead to diminished therapeutic efficacy over time, known as secondary nonresponse.

Objective: This review aims to bridge the knowledge gap regarding the immunogenic mechanisms of BoNT-A and to explore effective management strategies to mitigate these immune responses.

Materials and methods: The authors conducted a systematic search in databases including PubMed, Embase, and Web of Science, using keywords related to BoNT-A's immunogenicity. The selection process refined 157 initial articles down to 23 relevant studies, which underwent analysis to investigate the underlying mechanisms of immunogenicity and the factors influencing it.

Results: The analysis revealed that both the neurotoxin component and the neurotoxin-associated proteins could elicit an immune response. However, only antibodies against the core toxin influence therapeutic outcomes. Various patient-specific factors such as genetic predispositions and prior immune experiences, along with treatment-related factors such as dosage and frequency, play crucial roles in shaping these responses.

Conclusion: Understanding the specific immunogenic triggers and responses to BoNT-A is critical for optimizing treatment protocols and improving patient outcomes.

Background: Hypertrophied submandibular glands provide a bulky contour to the lower face. Botulinum neurotoxin injection methods are commonly used for facial contouring; however, no studies have suggested injection points because of the lack of delicate anatomical information on the submandibular gland.

Objective: The aim of this study was to determine the optimal injection site for botulinum neurotoxin injections in the submandibular gland.

Materials and methods: Anatomical considerations when injecting botulinum neurotoxin into the submandibular gland were determined using ultrasonography. The thickness of the submandibular gland, its depth from the skin surface, and the location of the vascular bundle were observed bilaterally in 42 participants. Two cadavers were dissected to measure the location of the submandibular gland corresponding to the ultrasonographic observation.

Results: The thickest part of the submandibular gland measured 11.12 ± 2.46 in width with a depth of 4.63 ± 0.76. At the point where it crosses the line of the lateral canthus, it measured 5.53 ± 1.83 in width and 8.73 ± 1.64 in depth.

Conclusion: The authors suggest optimal injection sites based on external anatomical landmarks. These guidelines aim to maximize the effects of botulinum neurotoxin therapy by minimizing its deleterious effects, which can be useful in clinical settings.

Background: Vitiligo treatment is challenging, especially for resistant and stable vitiligo, which requires surgical management. Noncultured epidermal cell suspension has been modified to enhance the treatment outcomes.

Objective: Comparison of autologous noncultured trypsinized epidermal cell suspension in recipient site prepared by cryoblebbling and noncultured nontrypsinized epidermal cell graft homogenized with plasma gel in recipient site prepared by dermabrasion for stable vitiligo treatment.

Materials and methods: Interventional comparative study on 30 patients with stable vitiligo, randomly divided into 2 equal groups. Group A: noncultured trypsinized epidermal cell suspension for recipient prepared by cryoblebbling. Group B: noncultured nontrypsinized epidermal cell graft homogenized with plasma gel for recipient prepared by dermabrasion. Afterward, both groups received 3 months of narrow-band ultraviolet B phototherapy.

Results: The plasma gel group showed a significantly earlier onset of repigmentation and faster healing ( p = .002* and <.001*, respectively). Overall, repigmentation was higher in the plasma gel group ( p = .037* at the end of the second month). Color matching and patient satisfaction were higher in the plasma gel group, without statistical significance. The cryobleb group showed more recipient site complications, and the plasma gel procedure was relatively easier and cheaper.

Conclusion: Plasma gel modification is cost-effective, less time-consuming, does not require trypsinization, and provides rapid, satisfactory, and uniform repigmentation. Cryoblebbing and trypsinization are effective; however, there are more technical difficulties, delayed healing, and delayed onset of repigmentation.

Background: Botulinum type-A toxin is a well established aesthetic and medical treatment. While the usage of type-B toxin is less common, there is a growing interest in using type-B toxin, especially in those who are treatment resistant.

Objective: To evaluate the primary FDA-approved clinical applications of rimabotulinumtoxinB, along with established and emerging off-label clinical indications.

Material and methods: Articles were reviewed from PubMed database and Food and Drug Adminstration guidelines.

Results: Facial rhytids tend to use a higher conversion ratio between type A and type B toxin, due to type B toxin's weaker affinity to muscles and higher affinity for sweat glands. Specially, a 1:100 to 1:50 ratio was utilized for glabellar rhytids, a 1:25 to 1:50 ratio for periocular rhytids, a 1:50 to 1:66.6 ratio for cervical dystonia, a 1:20 to 1:50 ratio for hyperhidrosis, and a 1:25 to 30 ratio for sialorrhea.

Conclusion: Type B toxin has demonstrated its safety and efficacy in treating facial rhytids, cervical dystonia, sialorrhea and hyperhidrosis, with potential for novel applications under investigation. Regardless of injection location and clinical applications, dry mouth and dysphagia remained the most common side effects. Across all indications, type B toxin appeared to have a faster onset of action, a dose-dependent clinical duration, and a dose-dependent adverse effect profile.

Background: Microneedling is used to enhance transcutaneous drug delivery. However, the extent to which microneedling devices impact filler delivery and whether this varies by filler type, microneedling device type, and treatment sequence is not known.

Objective: To histologically assess and quantify the delivery of commonly used fillers through microneedling, using both a microneedling pen and a microneedling roller. In addition, the authors investigated whether there is a variation in filler delivery based on the sequence of microneedling in relation to topical filler application.

Methods: Ex vivo human abdominal skin samples were subjected to microneedling pen or microneedling roller treatment. Black tissue marking ink, hyaluronic acid, poly- l -lactic acid, or undiluted calcium hydroxyapatite was topically applied before or immediately after microneedling treatment.

Results: Histological evaluation revealed a notable presence of black ink within channels formed by both microneedling treatments (15.5%-98.1%), whereas there was limited presence of the various filler types tested (0%-6.6%) in all settings. Topical application before microneedling treatment led to relatively higher filler/ink deposition within the channels formed by the microneedling treatments compared with topical application after microneedling.

Conclusion: Transcutaneous delivery of fillers was not significantly helped by microneedling treatment, whereas the microneedling devices demonstrated effective delivery of an aqueous solution.