Botulinum Toxin Type A is a potent neurotoxin that is produced by a gram‐positive bacteria clostridium botulinum. Its utilization in the treatment of various medical condition has expanded over the years in both medical and esthetic uses. It is being preferred by most physicians due to its efficacy and lack of side effects. It can be used as monotherapy or combined therapy. The aim of this review study was to show the role and mechanism of action of Botulinum toxin type A in the treatment and prevention of hypertrophic scars and keloids. The clear mechanisms underlying hypertrophic scars and keloids are still not clearly understood; however, the mechanism of action of Botulinum toxin type A has been shown to include action on wound tension, action on collagen, and action on fibroblasts. Different randomized controlled trials, double‐blind, and placebo‐controlled studies have been conducted to investigate its use in treatment and prevention of hypertrophic scars and keloids, and it still is one of the active areas of research in Dermatology and related fields. Method: In March 2018, we performed a literature search in PubMed for clinical studies, clinical trials, case reports, controlled trials, randomized controlled trials, and systemic reviews. The search terms we used were “BOTULINUM TOXIN” AND “HYPERTROPHIC SCARS” OR “KELOIDS” (from 1980). The search resulted in 1000 articles, out of these 35 articles met our inclusion exclusion criteria. Our inclusion criteria included relevant original articles relevant, critical systemic reviews, and crucial referenced articles, exclusion criteria included duplicates and articles not published in English language. We have reviewed these papers to show the role and mechanism of action of Botulinum toxin type A in the treatment and prevention of hypertrophic scars and keloids.

Background: Merkel cell carcinoma (MCC) is a rare and aggressive neuroendocrine carcinoma of the skin, with a high recurrence rate and a high mortality rate worldwide. The purpose of this article is to construct a nomogram that incorporates significant clinical parameters and predicts the survival of individuals with MCC. Methods:The Surveillance, Epidemiology, and End Results (SEER) database was employed to retrospectively analyze all confirmed MCC cases from 2004 to 2015. The data was collected from 3,688 patients, and was randomized as the training or validation group (1:1 ratio). The independent factors which predicted the cancer-specific survival (CSS) and overall survival (OS) for MCC cases were searched for nomogram construction respectively. Independent parameters that affected CSS were determined using the Fine and Gray competing risk regression model. In addition, the time-dependent receiver operating characteristic (ROC) curve was constructed. Then, the area under the curve (AUC) values, calibration curve, and the concordance index (C-index) were used to determine the nomogram performance. At last, decision curve analysis (DCA) was conducted to determine the net clinical benefit. Results:The multivariate analysis results revealed that sex, age, race, marriage, American Joint Committee on Cancer (AJCC) stage, chemotherapy and radiotherapy were independent OS prognostic factors.Furthermore, competing risk analysis showed age, sex, AJCC stage, chemotherapy were the independent CSS prognostic factors. For validation, the C-index value of OS nomogram was 0.703 (95% CI: 0.686-0.721), while C-index value of CSS nomogram was 0.737 (95% CI: 0.710-0.764). Both C-index and AUC suggested that nomograms had superior performance to that of the AJCC stage system. In addition, according to the calibration curve, both nomograms were capable of accurate prediction of MCC prognosis. The DCA showed that the net benefits of the nomograms were superior among various threshold probabilities than these of AJCC stage system. Conclusions:The present work established and verified the novel nomograms to predict the OS and CSS of MCC patients. If further confirmed in future studies, it may become another helpful tool for risk stratification and management of MCC patients.

Acitretin, an active metabolite of etretinate, is the most widely used systemic retinoid in the treatment of psoriasis. Several side effects of acitretin have been reported such as teratogenicity, cheilitis, xerosis, dyslipidemia, and photosensitivity. Here, we reported a case of acitretin-induced intermittent asymptomatic fever in a 79-year-old male psoriasis patient. To the best of our knowledge, only one such case has been reported in the literature so far. We report our case to draw clinical attention that acitretin may cause drug fever, which might not be a rare phenomenon.