Pediatric dermatofibromas: Truncal predominance in younger children.

Pediatric dermatofibromas are considered rare in young children and have not been well characterized, often misdiagnosed clinically. We performed a retrospective case series of children younger than 18 years with histopathologically diagnosed dermatofibromas at our institutions and evaluated age at onset and diagnosis, sex, lesion location, and size, associated symptoms, change over time, and pre-biopsy diagnosis. Overall, dermatofibromas were most common on the back and chest (20/53; 38%), followed by the legs (15/53; 28%) and arms (12/53; 23%) with the most common pre-biopsy diagnosis of "cyst" (23/53; 43%), followed by dermatofibroma (16/53; 30%), and pilomatricoma (12/53; 23%). Our study reinforces previous findings of truncal predominance of pediatric dermatofibromas, different from adults.

Persistent papules and plaques in systemic juvenile idiopathic arthritis.

A 6-year-old girl presented with nightly fever, persistent joint pain of the knees, ankles, lower back, and hip. Her skin lesions were evanescent salmon-colored patches along with persistent pruritic light to dark pink papules and plaques on her face, post-auricular scalp, trunk, thigh, and bilateral upper extremities. Skin biopsy supported the diagnosis of fixed papules and plaques of systemic juvenile idiopathic arthritis (sJIA). We report this case to highlight diagnostic features of this exceedingly rare cutaneous presentation of sJIA presenting with typical cutaneous salmon-colored evanescent eruptions.

Frictional melanosis: A pediatric case series.

We present a pair of cases detailing acquired hyperpigmented patches overlying the spinous processes of pediatric patients. These cases are consistent with a condition that has previously been documented in the adult population and is known by many names, including "Davener's dermatosis," "towel melanosis," and "lifa disease." We propose unifying these terms into a single standardized name, "frictional melanosis," when it is encountered in the pediatric setting. In presenting these findings, we hope that greater awareness and recognition of this benign condition in pediatric patients will decrease the need for biopsy and reduce family concern.

Concurrent Subcutaneous Panniculitis-like T-Cell Lymphoma and B-Cell Acute Lymphoblastic Leukemia in 2 Pediatric Patients.

Subcutaneous panniculitis-like T-cell lymphoma is a cutaneous lymphoma characterized by CD8+ T-cell infiltrate in the subcutis that is rare in children. Acute lymphoblastic lymphoma is the most common pediatric malignancy and often presents with fevers and pancytopenia. Herein, we report 2 pediatric patients presenting with subcutaneous panniculitis-like T-cell lymphoma and B-cell acute lymphoblastic lymphoma, distinct hematologic malignancies arising from different lymphoid lineages, with no identifiable germline cancer predisposition.

Café au lait spots: When and how to pursue their genetic origins.

Café au lait spots are common birthmarks seen sporadically and in association with several genetic syndromes. Dermatologists are often asked to evaluate these birthmarks both by other physicians and by parents. In some cases, it is challenging to know when and how to pursue further evaluation. Diagnostic challenges may come in the form of the appearance of the individual lesions, areas and patterns of cutaneous involvement, and associated features (or lack thereof). In this review, we aim to clarify when and how to evaluate the child with multiple or patterned café au lait spots and to explain some emerging concepts in our understanding of the genetics of these lesions.

Rare Vesiculopustular Eruptions of the Neonatal Period.

Numerous disorders present with vesiculopustular eruptions in the neonatal period, ranging from benign to life-threatening. Accurate and prompt diagnosis is imperative to avoid unnecessary testing and treatment for benign eruptions, while allowing for adequate treatment of potentially fatal disorders. In this review, we highlight several rare blistering diseases of the newborn. A diagnostic approach is outlined to provide clinicians with a framework for approaching a neonate with vesicles, pustules, or ulcers.

Epidermolysis bullosa simplex-generalized severe type due to keratin 5 p.Glu477Lys mutation: Genotype-phenotype correlation and in silico modeling analysis.

BACKGROUND/OBJECTIVES: Epidermolysis bullosa is a group of diseases caused by mutations in skin structural proteins. Availability of genetic sequencing makes identification of causative mutations easier, and genotype-phenotype description and correlation are important. We describe six patients with a keratin 5 mutation resulting in a glutamic acid to lysine substitution at position 477 (p.Glu477Lys) who have a distinctive, severe and sometimes fatal phenotype. We also perform in silico modeling to show protein structural changes resulting in instability. METHODS: In this case series, we collected clinical data from six patients with this mutation identified from their national or local epidermolysis bullosa databases. We performed in silico modeling of the keratin 5-keratin 14 coil 2B complex using CCBuilder and rendered with Pymol (Schrodinger, LLC, New York, NY). RESULTS: Features include aplasia cutis congenita, generalized blistering, palmoplantar keratoderma, onychodystrophy, airway and developmental abnormalities, and a distinctive reticulated skin pattern. Our in silico model of the keratin 5 p.Glu477Lys mutation predicts conformational change and modification of the surface charge of the keratin heterodimer, severely impairing filament stability. CONCLUSIONS: Early recognition of the features of this genotype will improve care. In silico analysis of mutated keratin structures provides useful insights into structural instability.

A pediatric case of squamous cell cancer in situ in the setting of sclerodermatous graft-versus-host disease and voriconazole treatment.

Sclerodermatous graft-versus-host disease is a subtype of cutaneous chronic graft-versus-host disease that is characterized by sclerosis of the skin and subcutaneous tissue, resulting in debilitating contractures, among other life-threatening complications. Children with sclerodermatous graft-versus-host disease are at high risk of developing nonmelanoma skin cancer because of several risk factors, including young age at transplantation, prolonged immunosuppression, and exposure to photosensitizing antimicrobial prophylaxis such as voriconazole. The immunosuppression required to treat sclerodermatous graft-versus-host disease makes effectively treating nonmelanoma skin cancer and sclerodermatous graft-versus-host disease in the same patient challenging. We describe a challenging case of a 6-year-old boy with a history of sclerodermatous graft-versus-host disease and voriconazole exposure presenting with squamous cell carcinoma in situ on the left temple and actinic keratoses on the scalp treated with topical chemotherapy agents.

Simultaneous flagellate erythema in a husband and wife secondary to shiitake mushroom ingestion.

Flagellate erythema secondary to shiitake mushroom (Lentinus edodes) ingestion is a condition that was first documented in 1977 by Nakamura and has been reported in Japan, Europe, and the United States. Herein, we present two cases of flagellate erythema after a couple ate a meal containing shiitake mushrooms at a chain restaurant. We hypothesize that this condition may not be as rare or as dependent on volume of exposure as previously suggested, considering that two genetically unrelated individuals simultaneously developed the eruption after minimal exposure.

Prepubertal Melanoma Arising within a Medium-Sized Congenital Melanocytic Nevus.

We report the case of an 8-year-old child who developed a 9.4-mm-deep melanoma within a medium-sized congenital melanocytic nevus on the scalp. Genetic analysis revealed an activating NRAS Q61R mutation within the melanoma, which is more commonly associated with large or giant congenital melanocytic nevi. This case demonstrates that even a "low-risk" congenital melanocytic nevus at a "low-risk" age must be monitored regularly for the development of malignancy.