Primary cutaneous Hodgkin-like polymorphic post-transplant lymphoproliferative disorder.

Post-transplant lymphoproliferative disorder (PTLD) is an uncommon complication after solid-organ transplants and hematopoietic stem cell transplants. Isolated involvement of the skin without systemic involvement in PTLD is extremely rare. Primary cutaneous PTLD is generally categorized as either cutaneous T-cell lymphoma or cutaneous B-cell lymphoma, with variable Epstein-Barr virus (EBV) positivity. Herein, we describe an exceedingly uncommon case of a primary cutaneous Hodgkin-like polymorphic PTLD. A man in his 60s, with a history of kidney transplant, presented with a 5-week history of two indurated plaques. Clinical, histologic and immunohistochemical findings were consistent with primary cutaneous Hodgkin-like polymorphic PTLD. Reduction in immunosuppression led to resolution of his lesions. This case highlights a rare case of primary cutaneous Hodgkin-like PTLD and increases awareness of this uncommon post-transplant complication. It also underscores the importance of collaboration between dermatology, hematology, dermatopathology and hematopathology in order to diagnose challenging cases.

Dermatologic manifestations in spaceflight: a review.

With manned missions to Mars on the horizon, understanding and preparing for the medical conditions these astronauts might face becomes vital. According to the literature, the most commonly reported medical events in space are dermatological in nature. Dermatologic conditions rarely threaten an astronaut's life or the mission. However, manifestations and management of dermatologic events become an important consideration in anticipation of spaceflights to Mars and beyond. Given the limited number of articles written about dermatological conditions in this specific population, this review summarizes current knowledge related to dermatology in space. Overall, common dermatologic conditions found during spaceflight include viral reactivations, contact dermatitis or eczematous patches, and skin infections. Diagnosis and treatment can be difficult given the lack of resources in space as well as the hazards and side effects of certain treatments. In this review article we aim to summarize common skin changes induced by spaceflight, describe previously reported skin conditions including current treatment options, explore the risk of skin cancer in this unique population, and address the challenge of remote diagnosis.

Differentiating Desquamating Skin Lesions: A Case of Methotrexate Epidermal Necrosis.

Desquamating skin lesions are a non-specific finding that requires urgent evaluation given the life-threatening severity of one of the potential causes, Stevens-Johnson syndrome (SJS). Methotrexate toxicity, also known in its cutaneous form as methotrexate epidermal necrosis (MEN), is another entity that presents similarly to SJS and is described here in a patient with increased risk due to his age, chronic kidney disease, and increased dose of methotrexate. His diagnosis was complicated by other historical risk factors, including antibiotic use, but was eventually elucidated when he was noted to have bone marrow suppression. Given the pathophysiology of SJS, a T-cell mediated reaction, the patient's leukopenia increased the likelihood of MEN as his ultimate diagnosis. However, in light of his aggressive treatment and non-specific histopathology, the clinical suspicion of MEN could not be confirmed.

Diffuse annular lesions.

This patient inadvertently complicated her own recovery by chalking up these lesions to a preexisting condition.

Human Health during Space Travel: State-of-the-Art Review.

The field of human space travel is in the midst of a dramatic revolution. Upcoming missions are looking to push the boundaries of space travel, with plans to travel for longer distances and durations than ever before. Both the National Aeronautics and Space Administration (NASA) and several commercial space companies (e.g., Blue Origin, SpaceX, Virgin Galactic) have already started the process of preparing for long-distance, long-duration space exploration and currently plan to explore inner solar planets (e.g., Mars) by the 2030s. With the emergence of space tourism, space travel has materialized as a potential new, exciting frontier of business, hospitality, medicine, and technology in the coming years. However, current evidence regarding human health in space is very limited, particularly pertaining to short-term and long-term space travel. This review synthesizes developments across the continuum of space health including prior studies and unpublished data from NASA related to each individual organ system, and medical screening prior to space travel. We categorized the extraterrestrial environment into exogenous (e.g., space radiation and microgravity) and endogenous processes (e.g., alteration of humans' natural circadian rhythm and mental health due to confinement, isolation, immobilization, and lack of social interaction) and their various effects on human health. The aim of this review is to explore the potential health challenges associated with space travel and how they may be overcome in order to enable new paradigms for space health, as well as the use of emerging Artificial Intelligence based (AI) technology to propel future space health research.

The rash that leads to eschar formation.

When confronted with an existent or evolving eschar, the history is often the most important factor used to put the lesion into proper context. Determining whether the patient has a past medical history of significance, such as renal failure or diabetes mellitus, exposure to dead or live wildlife, or underwent a recent surgical procedure, can help differentiate between many etiologies of eschars. Similarly, the patient's overall clinical condition and the presence or absence of fever can allow infectious processes to be differentiated from other causes. This contribution is intended to help dermatologists identify and manage these various dermatologic conditions, as well as provide an algorithm that can be utilized when approaching a patient presenting with an eschar.

Intraspecific differences in molecular stress responses and coral pathobiome contribute to mortality under bacterial challenge in Acropora millepora.

Disease causes significant coral mortality worldwide; however, factors responsible for intraspecific variation in disease resistance remain unclear. We exposed fragments of eight Acropora millepora colonies (genotypes) to putatively pathogenic bacteria (Vibrio spp.). Genotypes varied from zero to >90% mortality, with bacterial challenge increasing average mortality rates 4-6 fold and shifting the microbiome in favor of stress-associated taxa. Constitutive immunity and subsequent immune and transcriptomic responses to the challenge were more prominent in high-mortality individuals, whereas low-mortality corals remained largely unaffected and maintained expression signatures of a healthier condition (i.e., did not launch a large stress response). Our results suggest that lesions appeared due to changes in the coral pathobiome (multiple bacterial species associated with disease) and general health deterioration after the biotic disturbance, rather than the direct activity of any specific pathogen. If diseases in nature arise because of weaknesses in holobiont physiology, instead of the virulence of any single etiological agent, environmental stressors compromising coral condition might play a larger role in disease outbreaks than is currently thought. To facilitate the diagnosis of compromised individuals, we developed and independently cross-validated a biomarker assay to predict mortality based on genes whose expression in asymptomatic individuals coincides with mortality rates.