Topical rapamycin (sirolimus) for the treatment of uncomplicated tufted angiomas in two children and review of the literature

How we approach coagulopathy with vascular anomalies

Some vascular anomalies can present with challenging hematologic aberrations. Kaposiform hemangioendothelioma (KHE) may be complicated with Kasabach-Merritt phenomenon (KMP) and stagnant blood flow in slow-flow malformations can promote activation and consumption of coagulation factors, which results in bleeding and clotting known as localized intravascular coagulopathy (LIC). These patients can experience significant morbidity secondary to pain due to thrombosis and are at higher risk of hematologic complications during surgical procedures. No standard of care has been established to prevent or manage these complications. This review focuses on the management of coagulopathy in children and adults with vascular anomalies.

Systematic review of sirolimus in dermatological conditions

Sirolimus is a mammalian target of rapamycin inhibitor (mTORI) with anti-proliferative, antiangiogenic and immunosuppressive properties. While approved in Australia as an anti-rejection medication for renal transplant patients, there is mounting evidence regarding the utility of oral and topical sirolimus in treating a plethora of dermatological conditions or conditions with cutaneous manifestations. Our aim was to present an overview of the evidence for current usage and breadth of the application of sirolimus in dermatology. We carried out a systematic review of all the literature published up to 31 August 2019 on oral and topical sirolimus with respect to dermatological conditions or conditions otherwise relevant to dermatology. While 3368 papers were initially produced in our search, 238 papers met our inclusion criteria and were examined in our review. The conditions examined were categorised into genodermatoses (9 conditions), infection (1 condition), inflammatory/autoimmune (10 conditions), neoplasm (3 conditions) and vascular (17 conditions). We extracted data on first author, publication year, journal, characteristics of the study and study patients, condition, drug modalities, drug efficacy, side effects, blood level of mTORI, co-interventions and follow-up. While there is level 1 evidence for the efficacy of sirolimus in conditions such as tuberous sclerosis complex (TSC) and GVHD prophylaxis, for many other conditions, the evidence is limited to level 4 evidence. Regarding oral systemic therapy, dosing regimens varied with the most common for children 0.8mg/m² twice daily and for adults 1 mg twice daily. Doses were often adjusted to reach a typical trough level of between 5 and 15 ng/mL, though targets often varied. In the overall majority of cases, side effects were minimal or tolerable, including mucositis, cytopenias, lipid abnormalities and nausea/vomiting, and only a few cases had to stop due to adverse effects. Regarding topical therapy, concentration of formulations varied from 0.1% to 1% and were compounded into creams, ointments or gels and administered typically once or twice per day. The most common side effect was skin irritation. There were a number of limitations to our study. In particular, many of the published studies were case reports or case series with no comparator arm, leading to susceptibility of bias in conclusions drawn, in particular a high likelihood of publication bias. Given the heterogeneity amongst studies, comparisons or aggregation of results was difficult. There continues to be growing use of oral and topical sirolimus in dermatological conditions. It provides new therapeutic options to patients where previous therapies have either failed or are limited due to toxicity. However, further studies are warranted.

Topical sirolimus: Difference between compounded preparations and commercial oral solution

Topical sirolimus has become a crucial treatment option for many dermatologic disorders. Because an FDA-approved topical formulation is not commercially available, sirolimus creams, ointments, and gels are professionally prepared by compounding pharmacies. Also, the topical use of a commercially available sirolimus solution approved for oral administration is described regularly. To better guide providers in their decision-making when topical sirolimus is being considered, this article highlights the substantial pharmaceutical and clinical differences between commercial oral solution and compounded preparations specifically designed for topical therapy.

Vascular Anomalies of the Head and Neck: A Pediatric Overview

Vascular anomalies, further classified into vascular tumors and malformations, often involve the head and neck region of children. These entities may raise diagnostic dilemmas, as they often demonstrate heterogenous and overlapping histologic features. The aim of this paper is to provide an overview of the common vascular anomalies in the head and neck region of children. Specific entities discussed include infantile hemangioma, congenital hemangioma, tufted angioma, kaposiform hemangioendothelioma, and various vascular malformations. Clinicopathologic features and associated molecular associations are reviewed.

Sirolimus for Kaposiform Hemangioendothelioma With Kasabach-Merritt Phenomenon in Two Infants

Kaposiform hemangioendothelioma is an aggressive vascular tumor with infiltrative growth that commonly occurs in infancy and is associated with a life-threatening consumptive coagulopathy, as well as Kasabach-Merritt phenomenon. Recently, promising results have shown that sirolimus had been successfully used to treat Kasabach-Merritt phenomenon without significant toxicity. However, the situation the authors encountered in treating infants was not so satisfactory. Here, the authors present 2 patients younger than 3 months with refractory Kaposiform hemangioendothelioma treated with sirolimus and experienced severe pneumonia. The outcomes suggest that it is necessary to keep an eye on any symptoms indicate the infection of respiratory tract and use the antibiotics in time. The 2 cases also remind us of the potential sign that indicate the recurrence of KMP, which refers to firmer lesion with deepen color, especially when it comes with complications.

Kaposiform hemangioendothelioma: current knowledge and future perspectives

Kaposiform hemangioendothelioma (KHE) is a rare vascular neoplasm with high morbidity and mortality. The initiating mechanism during the pathogenesis of KHE has yet to be discovered. The main pathological features of KHE are abnormal angiogenesis and lymphangiogenesis. KHEs are clinically heterogeneous and may develop into a life-threatening thrombocytopenia and consumptive coagulopathy, known as the Kasabach-Merritt phenomenon (KMP). The heterogeneity and the highly frequent occurrence of disease-related comorbidities make the management of KHE challenging. Currently, there are no medications approved by the FDA for the treatment of KHE. Multiple treatment regimens have been used with varying success, and new clinical trials are in progress. In severe patients, multiple agents with variable adjuvant therapies are given in sequence or in combination. Recent studies have demonstrated a satisfactory efficacy of sirolimus, an inhibitor of mammalian target of rapamycin, in the treatment of KHE. Novel targeted treatments based on a better understanding of the pathogenesis of KHE are needed to maximize patient outcomes and quality of life. This review summarizes the epidemiology, etiology, pathophysiology, clinical features, diagnosis and treatments of KHE. Recent new concepts and future perspectives for KHE will also be discussed.