Paediatric-onset lymphomatoid papulosis: results of a multicentre retrospective cohort study on behalf of the EORTC Cutaneous Lymphoma Tumours Group (CLTG).

BACKGROUND: Lymphomatoid papulosis (LyP) is a rare cutaneous T-cell lymphoproliferative disorder. Comprehensive data on LyP in the paediatric population are scarce. OBJECTIVES: To characterize the epidemiological, clinical, histopathological and prognostic features of paediatric LyP. METHODS: This was a retrospective multicentre international cohort study that included 87 children and adolescents with LyP diagnosed between 1998 and 2022. Patients aged ≤ 18 years at disease onset were included. LyP diagnosis was made in each centre, based on clinicopathological correlation. RESULTS: Eighty-seven patients from 12 centres were included. Mean age at disease onset was 7.0 years (range 3 months-18 years) with a male to female ratio of 2 : 1. Mean time between the onset of the first cutaneous lesions and diagnosis was 1.3 years (range 0-14). Initial misdiagnosis concerned 26% of patients. LyP was most often misdiagnosed as pityriasis lichenoides et varioliformis acuta, insect bites or mollusca contagiosa. Erythematous papules or papulonodules were the most frequent clinical presentation. Pruritus was specifically mentioned in 21% of patients. The main histological subtype was type A in 55% of cases. When analysed, monoclonal T-cell receptor rearrangement was found in 77% of skin biopsies. The overall survival rate was 100%, with follow-up at 5 years available for 33 patients and at 15 years for 8 patients. Associated haematological malignancy (HM) occurred in 10% of cases (n = 7/73), including four patients with mycosis fungoides, one with primary cutaneous anaplastic large cell lymphoma (ALCL), one with systemic ALCL and one with acute myeloid leukaemia. If we compared incidence rates of cancer with the world population aged 0-19 years from 2001 to 2010, we estimated a significantly higher risk of associated malignancy in general, occurring before the age of 19 years (incidence rate ratio 87.49, 95% confidence interval 86.01-88.99). CONCLUSIONS: We report epidemiological data from a large international cohort of children and adolescents with LyP. Overall, the disease prognosis is good, with excellent survival rates for all patients. Owing to an increased risk of associated HM, long-term follow-up should be recommended for patients with LyP.

Lymphomatoid papulosis is a very rare skin condition caused by an abnormal increase in white blood cells (called 'lymphocytes') in the skin. The condition rarely affects children, so most of the scientific data published about this disease focuses on adults. This study involved 12 academic dermatology centres in Europe, the Middle East and North America, and gathered data from about 87 children who presented with symptoms of lymphomatoid papulosis before the age of 19 years. The aim of this study was to better describe this disease in the paediatric population and discuss its treatment options and evolution. We found that the presentation of the disease in children is roughly the same as in adults. Safe and effective treatment options exist. The disease is not life threatening, but it requires investigation by a dermatologist, both to make a careful diagnosis and to monitor it as sometimes associated cancers that originate from blood cells can occur, mostly on the skin.

[Clinical, therapeutic and pathophysiological aspects of Darier's disease]. / Aspects physiopathologiques cliniques et thérapeutiques de la maladie de Darier.

Darier Disease is a rare autosomal dominant inherited skin disorder classified as an acantholytic dermatosis. It manifests around puberty as brownish keratotic papules of skin folds and seborrheic areas, associated with onychopathy and mucosal involvementand have a chronic relapsing-remitting course with frequent exacerbations triggered by sun exposure, heat, friction, or infections. Darier patients have an increased risk of neuropsychiatric disorders, type 1 diabetes and heart failure. Short-term management relies on antibiotics/antiviral, topical corticosteroids and/or retinoids. Moisturizers, sun protection and avoiding triggers are essential for long-term management. Conventional long-term treatment is not standardized and many topical treatments, physical and surgical measures and systemic treatments are described in the literature.

La maladie de Darier est une génodermatose rare à transmission autosomique dominante. Elle se manifeste autour de la puberté par des papules kératosiques brunâtres des plis et des zones séborrhéiques, associées à une onychopathie et une atteinte muqueuse, et évolue par poussées déclenchées par les UV, la chaleur, les frottements ou les infections. Les patients atteints présentent un risque accru de diabète de type 1, d'insuffisance cardiaque et de troubles neuropsychiatriques. La prise en charge à court terme consiste en des antibiotiques/antiviraux, des corticostéroïdes topiques et/ou des rétinoïdes. Celle à long terme repose sur les émollients et l'éviction des facteurs déclenchants. Le traitement à long terme n'étant pas codifié, de nombreux traitements locaux et sytémiques, mesures physiques et chirurgicales sont décrits dans la littérature.

What is new about primary cutaneous B cell lymphomas.

Primary cutaneous B-cell lymphomas (CBCL) are a heterogeneous group of B-cell lymphomas without evidence of extracutaneous disease at the time of diagnosis. The 2022 World Health Organization classification of mature lymphoid neoplasms differentiates the indolent primary cutaneous marginal zone lymphoproliferative disorder, primary cutaneous follicle center lymphoma and Epstein-Barr virus-positive mucocutaneous ulcer, from the more aggressive primary cutaneous diffuse large B-cell lymphoma, leg-type and intravascular large B-cell lymphoma. The new updates in the 2022 classification are based on recent scientific advances in the understanding and characterization of these entities. This article aims to review the main clinical, cellular and molecular features of the five CBCL subsets along with their management and treatment. The exponentially growing evidence for new treatment options for systemic B-cell lymphomas raises expectations for the field of CBCL as well. However, specific prospective high quality research on CBCL is still crucial to further define their management and update international guidelines.

[Tinea capitis: new insights into an old disease]. / Tinea capitis: actualité d'une pathologie ancienne.

Tinea capitis is a superficial dermatophytic infection of the scalp. This common dermatosis occurs predominantly in children. The clinical manifestation of the disease is heterogeneous, and vary widely depending on the pathogenic fungal agent. Direct mycological examination and cultures are mandatory for an accurate diagnosis and species identification. Treatment should be both local and systemic, and ideally is tailored to the dermatophytic species identified by the laboratory diagnostic work up. Secondary prophylaxis through supplementary measures is crucial to avoid epidemic outbreak and patient reinfection.

Tinea capitis (ou teigne du cuir chevelu) est une infection fongique superficielle du cuir chevelu par un dermatophyte. Cette dermatose est fréquente et prédomine en population pédiatrique. Le tableau clinique est hétérogène et varie beaucoup en fonction de l'espèce de dermatophyte associée. L'examen mycologique direct et des cultures doivent être effectués pour un diagnostic précis et une identification de l'espèce. Le traitement devrait être à la fois local et systémique, et adapté au diagnostic de l'espèce dermatophyte identifiée en laboratoire de mycologie. La prophylaxie secondaire, par des mesures associées, est déterminante pour limiter l'émergence de foyers épidémiques ou la réinfection du patient.

Mogamulizumab Combined with Extracorporeal Photopheresis as a Novel Therapy in Erythrodermic Cutaneous T-cell Lymphoma.

BACKGROUND: Primary cutaneous T-cell lymphomas (CTCLs) are rare lymphoproliferative malignancies characterized by significant morbidity and mortality in advanced disease stages. As curative approaches apart from allogeneic stem cell transplantation are lacking, establishing new treatment options, especially combination therapies, is crucial. METHODS: This retrospective study included 11 patients with SS or MF receiving therapy with mogamulizumab in combination with ECP from four European expert centers. The response rates in the skin and blood as well as treatment use and adverse events (AE) were described. RESULTS: 8/11 patients (73%) showed an overall response (OR) in the skin. The mean mSWAT decreased from 98.2 ± 40.8 to 34.6 ± 23.8. The overall response rate (ORR) in the blood was 64% with two complete responses. During combination therapy, the mean number of Sézary cells decreased from 3365.3 × 106/L before treatment to 1268.6 × 106/L. The mean minimum known period without progress was 7.2 months in the skin and 7.6 months in the blood. The most common AEs were mogamulizumab-associated rash (MAR) (45.5%), anemia (27.3%), lymphocytopenia (27.8%), and infusion related reaction (16.7%). No AE led to treatment discontinuation. CONCLUSIONS: Our study presents the combination of mogamulizumab and ECP as an effective therapy in the blood and skin in CTCL with good tolerability, similar to mogamulizumab monotherapy.