Mucocutaneous toxicities from MEK inhibitors: a scoping review of the literature.

BACKGROUND: MEK inhibitors cause a wide spectrum of mucocutaneous toxicities which can delay or interrupt life-saving therapy. PURPOSE: To summarize the morphology, incidence, and clinical presentation of mucocutaneous toxicities from MEK inhibitors via a scoping review of the literature. METHODS: We conducted a scoping review of the published literature, including clinical trials, retrospective and prospective studies, reviews, and case reports and series. All included literature was analyzed by a panel of pediatric and adult oncodermatologists. RESULTS: Of 1626 initial citations, 227 articles met final inclusion criteria. Our review identified follicular reactions, ocular toxicities, xerosis, eczematous dermatitis, edema, and paronychia as the most common mucocutaneous side effects from MEK inhibitor therapy. Grade 1 and 2 reactions were the most prevalent and were typically managed while continuing treatment; however, grade 3 toxicities requiring dose reductions or treatment interruptions were also reported. CONCLUSION: Mucocutaneous toxicities to MEK inhibitor therapy are common and most often mild in severity. Early recognition and treatment can mitigate disruptions in oncologic therapy.

Neutrophilic dermatosis in a patient with an IKZF1 variant and a review of monogenic autoinflammatory disorders presenting with neutrophilic dermatoses.

Monogenic diseases of immune dysregulation should be considered in the evaluation of children presenting with recurrent neutrophilic dermatoses in association with systemic signs of inflammation, autoimmune disease, hematologic abnormalities, and opportunistic or recurrent infections. We report the case of a 2-year-old boy presenting with a neutrophilic dermatosis, found to have a novel likely pathogenic germline variant of the IKAROS Family Zinc Finger 1 (IKZF1) gene; the mutation likely results in a loss of function dimerization defective protein based on reports and studies of similar variants. IKZF1 variants could potentially lead to aberrant neutrophil chemotaxis and development of neutrophilic dermatoses. Long-term surveillance is required to monitor the development of hematologic malignancy, autoimmunity, immunodeficiency, and infection in patients with pathogenic IKZF1 germline variants.

How we approach hemangiomas in infants.

Pediatric oncologists are increasingly involved in the management of benign vascular tumors and their associated life-threatening complications. Hemangiomas are the most common referring diagnosis to multidisciplinary vascular anomalies clinics. However, as contemporary research has revealed, hemangiomas are not a single, easily defined entity but rather a diverse set of related vascular tumors, each having a unique natural history, growth pattern, and response to therapy. This manuscript seeks to illustrate how we evaluate and manage these complex tumors, their complications, and associated syndromes, while remaining ever vigilant for malignant hemangioma mimickers such as soft tissue sarcomas and congenital leukemia.

The "bumpy" adolescent nose: Acne associated angiofibroma-like nasal papules.

BACKGROUND/OBJECTIVE: Papular scars are a recently described clinical phenotype of acne scarring characterized by papules occurring on the nose and chin. We have observed a similar presentation of nasal papules among patients seen in our clinic for acne and sought to further characterize the clinical and histopathological characteristics of this entity. METHODS: In this single-site case series, a retrospective review of electronic medical records of patients with nasal papules in association with acne vulgaris between April 2018 and April 2019 was performed. Clinical and histopathologic findings were recorded. RESULTS: We identified 20 patients who presented with a similar clinical phenotype of predominantly skin-colored, dome-shaped papules concentrated on the nose and chin in association with a history of more classic facial acne vulgaris. Papular lesions were seen predominately in adolescent Hispanic males. Concomitant acne on other areas of the face was identified in 18 patients at presentation while two patients had a history of adolescent acne. Biopsies were performed for five patients. Histopathologic examination demonstrated features of fibrosis and dilated thin-walled blood vessels, typical of angiofibromas. CONCLUSION: We present a series of adolescent patients with large, flesh-colored to erythematous papules seen predominantly on the nose. These lesions are histologically indistinguishable from angiofibromas and may represent an under-recognized yet disfiguring sequela of acne that may disproportionately affect adolescents with skin of color.

Dabrafenib-induced neutrophilic panniculitis in a child undergoing dual BRAF-MEK inhibitor therapy for glioblastoma multiforme.

BRAF inhibitor-induced neutrophilic panniculitis is a rare event that is well-characterized in adults undergoing therapy for metastatic melanoma. To date, there are very few reports of this event in children undergoing BRAF inhibitor therapy for low-grade gliomas, all of which were seen with vemurafenib. We report a case of dabrafenib-induced neutrophilic panniculitis in a 9-year-old girl that manifested within several weeks of initiating dual BRAF-MEK inhibitor therapy for glioblastoma multiforme. This case highlights neutrophilic panniculitis as a side effect of dabrafenib in children and serves as a reminder to consider cutaneous side effects of BRAF inhibitors as they are increasingly used to treat children with primary brain tumors.

Exanthematous Eruptions in Children.

Childhood exanthems are commonly encountered by pediatricians in the hospital and the office. In the last several decades, we have seen a shift in the epidemiology of many of these diseases. After being deemed eliminated at the turn of 21st century, measles has experienced a resurgence secondary to falling vaccination rates, raising public health concerns. A new variant of hand, foot, and mouth disease caused by coxsackievirus A6 has been associated with more widespread and atypical disease, which can present diagnostic challenges to clinicians. Parvovirus B19, which is traditionally associated with fifth disease, is also the leading cause of papular purpuric gloves and socks syndrome, a rare condition with which providers may be unfamiliar. Since the introduction of routine vaccination, there has been a shift in the epidemiology and clinical presentation of primary varicella and herpes zoster. Finally, the recently described phenomenon of Mycoplasma pneumoniae-induced rash and mucositis will be discussed. [Pediatr Ann. 2020;49(3):e116-e123.].

Nevus psiloliparus: Newly described histopathological features from transverse sections.

Nevus psiloliparus is a rare fatty tissue nevus that is a marker for encephalocraniocutaneous lipomatosis, a neurocutaneous syndrome with ocular and central nervous system anomalies. Clinically, nevus psiloliparus is often described as a congenital alopecia and appears as an irregularly shaped, circumscribed area of alopecia on the scalp. Histopathology demonstrates a near-complete absence of mature hair follicles with preservation of arrector pili muscles and mature adipocytes within the dermis. The pathogenesis of nevus psiloliparus may be related to mosaic mutations in fibroblast growth factor receptor 1. Herein we report the histopathological features of a nevus psiloliparus in an 11-year-old girl diagnosed from transverse sections, which show "shadow" follicular units characterized by columns of loosely arranged collagen and a relative paucity of elastic fibers.

A case of recalcitrant pediatric Vogt-Koyanagi-Harada disease successfully controlled with adalimumab.

Vogt-Koyanagi-Harada (VKH) disease is uncommon in the pediatric population and can have an aggressive course with serious visual sequelae. A 12-year-old Han Chinese American female, who presented with mild headaches and panuveitis with diffuse serous retinal detachments, was diagnosed with VKH. Despite treatment with a combination of high-dose systemic corticosteroids, intravitreal triamcinolone injection, and mycophenolate mofetil, ocular inflammation was inadequately controlled. Addition of adalimumab allowed for inflammation remission, improvement of vision, and tapering of systemic corticosteroids. Escalation of immunosuppression until remission appears to be critical in this population. Further research is needed to understand the complex pathophysiology of VKH and investigation for similar efficacy of other anti-tumor necrosis factor-alpha agents will need to be performed.

Congenital-type juvenile xanthogranuloma: A case series and literature review.

BACKGROUND/OBJECTIVES: Congenital juvenile xanthogranulomas are infrequently described in the medical literature. We report three previously unpublished cases and systematically review the literature to better characterize this variant. METHODS: We surveyed English-language articles indexed in MEDLINE (1951-March 2017) and EMBASE (1974-March 2017) for cases of congenital-onset juvenile xanthogranulomas confirmed on histopathology. Cases were divided into two categories: cutaneous only or cutaneous with systemic involvement. RESULTS: We identified 31 cases of congenital juvenile xanthogranulomas involving only the skin and 16 cases with systemic involvement. Congenital juvenile xanthogranulomas involving only the skin were large (> 3 cm), presented with various clinical morphologies, and showed signs of regression by 1 year of age. Atypical clinical presentations included exophytic tumors, infiltrative plaques, agminated plaques, and subcutaneous tumors. Complications included ulceration and anetodermic scarring. Infants with congenital cutaneous juvenile xanthogranulomas who also had systemic involvement typically had multiple cutaneous tumors and hepatic involvement and showed signs of spontaneous regression independent of treatment. CONCLUSIONS: The medical literature supports that congenital juvenile xanthogranulomas behave in a fashion similar to that of juvenile xanthogranulomas of infancy or childhood. Congenital cutaneous juvenile xanthogranulomas with or without systemic involvement spontaneously regress. The varied clinical presentations in the skin may lead to misdiagnosis, inappropriate examination, and unnecessary treatments. Infants with multiple congenital cutaneous juvenile xanthogranulomas should be evaluated for systemic involvement, with a particular focus on the liver, because 72.2% of these children were found to have hepatic juvenile xanthogranulomas.

Tick bite mimicking indeterminate cell histiocytosis.

Ticks are a well-known vector for viral, bacterial, and rickettsial infections, many of which are accompanied by cutaneous eruptions, but the bite itself can induce a spectrum of inflammatory reactions, including foreign body granuloma, tick bite alopecia, and cutaneous lymphoid hyperplasia. We describe the development of an indeterminate cell histiocytic infiltrate at the site of a tick bite. Although the etiology of intermediate cell histiocytosis is not well understood, this case raises the possibility that such infiltrates may represent an inflammatory reaction in some patients.

Eosinophilic Pustular Folliculitis in Children after Stem Cell Transplantation: An Eruption Distinct from Graft-Versus-Host Disease.

Eosinophilic pustular folliculitis (EPF) is a rare cutaneous disorder that typically occurs in three clinical contexts: men, individuals who are immunosuppressed or have human immunodeficiency virus, and infants. A fourth subtype occurring 2 to 3 months after hematopoietic stem cell transplantation (HSCT) has recently been described in several adults. We report two cases of EPF arising in children after HSCT. It is important to recognize this form of EPF after HSCT and differentiate it from graft-versus-host disease since it responds readily to topical steroids and appears to have an excellent prognosis.

Fetal Alcohol Exposure and PHACE Syndrome: A Case and Autopsy Report.

This report describes the clinical, radiologic, and autopsy findings of a newborn with PHACE syndrome (posterior fossa malformations, hemangioma, arterial anomalies, cardiac defects, and eye anomalies) and fetal alcohol spectrum disorder. To our knowledge, the concurrence of these conditions has not been reported in the literature.

Role of Sirolimus in Advanced Kaposiform Hemangioendothelioma.

Kaposiform hemangioendothelioma (KHE) is an infiltrative vascular tumor that classically presents in infancy. Management typically focuses on treating Kasabach-Merritt phenomenon (KMP), a disorder of severe and at times life-threatening platelet trapping. However, the morbidity of KHE extends beyond KMP. The infiltrative nature of the tumor can lead to long-term disability and often makes complete surgical resection impossible. We report the case of a 10-year-old boy with a KHE of his right distal thigh who was unable to walk without assistance due to fibrotic change and right knee contracture. He had no laboratory evidence of KMP at the time of representation. Rapamycin was started in hopes of reducing the tumor burden. Within 2 months of therapy, fibrotic areas softened, his contracture nearly resolved, and there was marked improvement in his mobility. Rapamycin has been previously reported to be effective in managing cases of KHE complicated by KMP. Our report emphasizes the role for rapamycin in the treatment of KHE in the absence of KMP through the inhibition of vasculogenesis and fibrotic pathways.

A case of hair re-pigmentation from a scalp melanoma.

Hair re-pigmentation in adults is a rare phenomenon. We describe a 58-year-old woman who developed hair re-pigmentation on her vertex scalp as a marker of underlying melanoma. Histopathology revealed a nodular melanoma that was surrounding but not invading follicular epithelium. To our knowledge, there have only been 4 other previously published cases describing hair re-pigmentation in the setting of scalp melanoma. Focal hair re-pigmentation in adults should prompt a thorough evaluation for an underlying melanoma.