Extranodal Follicular Dendritic Cell Sarcoma Presenting on the Skin.

ABSTRACT: Follicular dendritic cell sarcoma is a rare intermediate-grade malignancy characterized by a proliferation of ovoid to spindle-shaped cells with morphologic and immunophenotypic features similar to normal follicular dendritic cells. It may develop in lymph nodes or extranodal sites. Its presentation in extranodal tissues is a diagnostic challenge. It requires a high index of suspicion because follicular dendritic cell markers are not included in the routine immunohistochemical panels used for differential diagnosis. In an extensive review of the English literature, we found 3 cases of follicular dendritic cell sarcoma developing on the skin. We report a case of a primary cutaneous follicular dendritic cell sarcoma in a 28-year-old man, which presented as a 6-mm skin-colored nodule on the right forearm. We describe the morphologic and immunohistochemical features and a review of the literature.

International Dermatology Outcome Measures (IDEOM) - Report from the 2022 Annual Meeting.

BACKGROUND: The International Dermatology Outcome Measures (IDEOM) is a non-profit organization dedicated to the advancement of evidence-based, consensus-driven outcome measures in dermatological diseases. Researchers and stakeholders from various backgrounds collaborate to develop these objective benchmark metrics to further advance treatment and management of dermatological conditions. SUMMARY: The 2022 IDEOM Annual Meeting was held on June 17-18, 2022. Leaders and stakeholders from the hidradenitis suppurativa, acne, vitiligo, actinic keratosis, alopecia areata, itch, cutaneous lymphoma, and psoriatic disease workgroups discussed the progress of their respective outcome-measures research. This report summarizes each workgroup's updates from 2022 and their next steps as established during the 2022 IDEOM Annual Meeting. J Drugs Dermatol. 2023;22(12):1153-1159 doi:10.36849/JDD.7615.

Patterns of Recurrence of Cutaneous Melanoma: A Literature Review.

The incidence of melanoma has been dramatically increasing over the last decades. Melanoma is considered to have a high metastatic potential and it can progress via lymphatic vessels or through hematogenous metastasis. Different patterns of recurrence have been described, namely, local, satellite, and in transit metastasis (LCIT), lymphatic metastasis, and systemic metastasis. With a more advanced melanoma stage at diagnosis, there is a higher risk for systemic metastasis in comparison to LCIT; in contrast, early-stage melanoma tends to recur more frequently as LCIT and less commonly as systematic metastasis. The aim of this review was to summarize the patterns of recurrence of cuta-neous melanoma, giving the clinician a practical summary for diagnosis, prognosis, and surveillance. There is a knowledge gap of the common patterns of recurrence that needs to be addressed to better identify patients at high risk of disease recurrence and personalize surveillance strategies as well as patient counseling.

Interleukin (IL)-17 Versus IL-23 Inhibitors: Which Is Better to Treat Patients With Moderate-to-Severe Psoriasis and Mild Psoriatic Arthritis in Dermatology Clinics?

Interleukin (IL)-17 and IL-23 inhibitors are both approved for the treatment of moderate-to-severe plaque psoriasis (PsO), as well as psoriatic arthritis (PsA). In the absence of head-to-head studies, it is not clear which agent is better suited to treat patients with moderate-to-severe PsO and mild PsA. During the 2022 Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) conference, Dr. April Armstrong and Dr. Joseph Merola debated which of these 2 biologic classes should be used in this patient population. Armstrong argued in favor of IL-17 inhibition, whereas Merola presented reasons for IL-23 inhibition. An overview of their main arguments is described in this manuscript.

Dermatitis de contacto fotoalérgica y test de fotoparches: revisión de la literatura y aplicación de la técnica en clínica alemana de Santiago / Photoallergic contact dermatitis and test photopatches: literature review and application of the technique at clínica alemana de Santiago

Las fotodermatosis son un conjunto de patologías cutáneas originadas o agravadas por exposición a radiación ya sea solar o artificial. Se clasifican en cuatro categorías: 1. Idiopáticas o mediadas inmunológicamente 2. Dermatosis fotoagravadas, 3. Fotosensibilidad inducida por agentes y 4. Trastornos por reparación defectuosa del ADN. La fotosensibilidad inducida por agentes consiste en reacciones secundarias a la exposición de ciertos químicos, llamados fotosensibilizadores y a distintos tipos de radiación lumínica. Los fotosensibilizadores pueden ser de origen endógeno o exógeno, aquellos exógenos provienen desde el ambiente, fármacos u otros productos (tanto sistémicos como tópicos), los cuales sufren modificaciones estructurales al entrar en contacto con radiación, provocando como consecuencia, distintas manifestaciones cutáneas. En este artículo se revisarán principalmente las reacciones fototóxicas y fotoalérgicas (ambas, reacciones de fotosensibilidad inducidas por agentes exógenos) indagando en sus diferencias y el enfrentamiento clínico de cada una. También, se revisarán los exámenes que permiten estudiar los distintos diagnósticos diferenciales, especialmente el test de fotoparches, el cual está cobrando cada vez más importancia en la práctica clínica.

Photodermatoses are a group of skin diseases induced or aggravated by exposure to radiation, whether solar or artificial. They are classified into four general categories: 1. Idiopathic or immunologically mediated photodermatoses 2. Photoexacerbated dermatoses 3. Agent induced photosensitivity 4. DNA repair defects Photosensitivity induced by agents are secondary reactions to the exposure to some chemicals, called photosensitizers, and to different types of light radiation. Photosensitizers can be classified as exogenous or endogenous. Exogenous agents come from the environment, drugs or other products (both systemic and topical), which undergo structural changes when they come into contact with radiation, causing different skin manifestations as consequence. Differences between phototoxic and photoallergic reactions (both photosensitivity reactions induced by exogenous agents), the clinical approach of each one of them, and available tests that are used to make a diagnosis, especially, photo patch test will be reviewed in this article