Cutaneous leishmaniasis: advances in disease pathogenesis,diagnostics and therapeutics

Cutaneous leishmaniasis is one of the most common tropical dermatoses worldwide and is of major public health importance. It is caused by numerous Leishmania protozoa species, which are responsible for its clinical diversity. With changes in vector (sandfly) habitat and increased travel among human populations, its incidence is rising, and in nonendemic countries, including the UK, it is increasingly diagnosed in migrants, returned travellers, and military personnel. Diagnostic tests have not always been sufficiently sensitive, and despite a wide range of treatments, poor therapeutic responses and adverse effects are common. In the past decade, there have been notable advances in molecular diagnostics, in the understanding of host immune responses to infection, and in new therapeutic interventions and vaccine development.     

New perspectives on dandruff and seborrheic dermatitis: lessons we learned from bacterial and fungal skin microbiota

The human body is inhabited by complex microbial communities, which positively impact different aspects of our health, and might also be related to the development of diseases. Progress in technologies, particularly sequencing methods and bioinformatics tools, has been crucial for the advances in this field. Microbial communities from skin can modulate immune response and protect the host against pathogens, and there are also data supporting their association with several skin conditions; including dandruff and seborrheic dermatitis. For decades, they have been thought to be related to Malassezia yeasts; however, the microbial role has not been elucidated, and their etiology remains poorly understood. This review discusses the recent findings in dandruff and seborrheic dermatitis and their relation to the skin microbiota. Data provided new perceptions to aid in the understanding of these skin disorders, broadening our view of their etiology and the possible roles of microbial communities in symptom development.     

Host defenses in subcutaneous mycoses

Subcutaneous mycoses include diverse clinical syndromes, characterized by invasion of the skin and subcutaneous tissue by saprobic fungi. Individuals living in rural areas constantly suffer lesions or trauma; however, only a few of them develop disease. In this contribution, we describe recent advances in the understanding of the virulence of these organisms, focusing on the most prevalent infections, sporotrichosis, chromoblastomycosis, and mycetoma. Although these infectious diseases are considered neglected tropical diseases, modern molecular techniques have been able to identify the etiologic agents and observe variations in the former monolithic concept of the species, which was based mostly on morphologic characteristics. The complete genetic characterization of the causative agents, along with that of their host, will help in the understanding of the factors on which the development of these infections depends.     

Tropical dermatology: fungal tropical diseases

Fungal infections are common in tropical countries and can have an important impact on public health. Lobomycosis is a common fungal infection in the tropical rain forest of South America, and paracoccidioidomycosis (South American blastomycosis) is a widespread and sometimes severe illness. Penicilliosis marneffei is an opportunistic infection of AIDS patients in southeast Asia. Chromoblastomycosis and mycetomas are causes of morbidity around the world. Sporotrichosis is a worldwide subcutaneous mycosis with a high incidence in tropical countries and is an important illness in immunocompromised patients. Rhinosporidiosis was classed as a fungal infection but is now considered a protistan parasite that belongs to the class Mesomycetozoea. It is included in this review because of its historical classification. In the past, most of these mycoses were restricted to specific geographic areas and natural reservoirs. There are, however, situations in which people from other regions come in contact with the pathogen. A common situation involves an accidental contamination of a traveler or worker who has contact with a tropical mycosis. Even minor trauma to the skin surface or inhalation of the fungal conidia can infect the patient. Thus recognition of the clinical symptoms and the dermatologic findings of the diseases, as well as the geographic distribution of the pathogens, can be critical in diagnosis of the tropical mycoses. This review discusses some of the more common tropical subcutaneous and systemic mycoses, as well as their signs, symptoms, methods of diagnosis, and therapies. LEARNING OBJECTIVE: At the completion of this learning activity, participants should be able to recognize the clinical and histologic presentations of tropical fungal diseases with cutaneous manifestations and be familiar with the appropriate therapies.     

Bedeutung der Dermatohistologie in der tropen- und reisedermatologischen Diagnostik

Background

Skin diseases are frequent in tropical countries and cause a significant burden for their health systems. Tropical dermatoses are frequently of infectious nature.

Diagnostics

Dermatopathology plays an important role in the diagnosis of many tropical skin diseases. This refers specially to leishmaniasis, tropical helminthic diseases, tuberculosis, leprosy, and deep fungal infections. In addition, dermatopathology is important for the differential diagnosis of non-infectious inflammatory diseases in pigmented skin; their identification may be more challenging than when seen in Caucasian skin.

Conclusion

While it is usually not problematic to perform a dermatopathologic workup in travelers and expatriates returning from the tropics into Western industrialized countries, dermatopathologic services are frequently non-existent or severely limited in many tropical countries. Therefore, in improving health systems, not only should a dermatologic workforce be developed, but also training of dermatopathologists and the establishment of dermatopathology laboratories should be considered.     

Gonococcal urethral stricture and watering-can perineum.

A total of sixteen patients with urethral stricture and/or perineal urinary fistulae (water-can perineum) complicating gonorrhoea were seen at the Special Treatment Clinic, University College Hospital, Ibadan, Nigeria. The patients were aged between 25 and 80 years, and the latent period between the time of original attack of gonococcal infection and the development of complications varied from 4 to 50 years. The rate of divorce or marital separation is high among these patients with late sequelae of gonorrhoea. The factors responsible for the present higher incidence of early and late complications of gonorrhoea among patients in Nigeria and other tropical countries compared with their counterparts in Europe and North American include: (a) Lack of medical facilities in most rural areas; (b) Inadequate treatment of veneral diseases, including the urban areas where self-medication is practised on a large scale by the general population; (c) Illiteracy and ignorance of venereal diseases. The cases of watering-can perineum reported here, and the subsequent chronic pyelonephritis and hypertension, reinforce the plea for early and energetic treatment of acute gonorrhoea in Africa as well as large-scale control measures by the health authorities.     

Lower‐extremity ulcers: diagnosis and management

Chronic wounds of the lower extremities are occurring with increasing prevalence. They affect millions of individuals annually, representing both a significant health risk and a large economic burden. Chronic wounds are associated with increased mortality and substantial morbidity due to infection, pain, limitation of daily activities, and psychosocial consequences. To manage these wounds effectively, clinicians must be able to diagnose and manage their aetiology. Diagnosis starts with determining whether the wound is one of the four most common chronic wounds: venous leg ulcers, diabetic foot ulcers, pressure ulcers and arterial ulcers. Moreover, despite many recent advances in wound care, the challenge of managing chronic wounds is complicated by the lack of consistently accepted diagnostic methods and wound‐care standards. We present a comprehensive yet condensed approach to managing lower‐extremity ulcers, from diagnosis to basic management.     

New and re-emerging cutaneous infectious diseases in Latin America and other geographic areas

Due to environmental factors and inadequate public health measures in many developing countries, new tropical infections, as well as infections that were previously isolated to remote locales, are becoming more prevalent in several areas of Latin America. This article discusses some tropical infections and infestations with predominantly cutaneous manifestations. Previously uncommon diseases such as gnathostomiasis, mycobacteria ulcerans infection, paederus dermatitis, Balamuthia mandrillaris infection, and human T-lymphotrophic virus 1 dermatitis are increasingly being reported. Well-known tropical infections such as bartonellosis, leishmaniasis, chromomycosis, larva migrans, and larva currens are also becoming more prevalent. On the other hand, the incidence of Hansen's disease, the quintessential tropical infection, is dwindling all over the globe thanks to a highly effective eradication campaign launched by the World Health Organization. Because of increased immigration and tourist travel, the number of cases of these diseases in the United States may escalate.     

Photodermatitis – study of the condition in Kuantan, Malaysia

The high incidence of photodermatitis among dermatological patients prompted the study of the condition. In the 18 months from October 1972 to March 1974, 199 patients presented with light sensitive dermatitis, forming 9% of all new cases seen in the Dermatology Clinic at Kuantan. A detailed history, including that of the use of drugs, proprietary and commercial products, was taken in each patient to determine the aetiology. Where there was suspicion of contact sensitisation, photo-patch tests were done with the suspected agents using natural sunlight as a source of ultra-violet light. The aetiology of photodermatitis in these patients is discussed. The systemic and topical use of medicaments accounts for the largest number of cases. It is inferred that the ready availability to the public of medicaments containing known photosensitisers and the unawareness of light sensitive dermatitis are factors responsible for the large number of patients developing this condition in this tropical climate where there is an abundance of ultra-violet light and where people wear light clothing.     

Cosmeceuticals: peptides,proteins, and growth factors

Recent research advances in the molecular and biochemical processes involved in wound healing and skin aging have led to the development of innovative cosmeceuticals that rely on peptides, proteins, and growth factors to enhance skin health. Although the long‐term benefits of these products have not been fully tested and evaluated, evidence of the benefits derived from their use is steadily growing. This study describes the peptides, proteins, and growth factors that are most frequently used in cosmeceuticals and discusses their potential benefits and practical use in dermatology.     

Mitochondria: a new focus as an anti‐aging target in skin care

Mitochondria, long considered to have the primary role in cellular energetic, have been the center of much research interest in the recent past. Technological advances in microscopy and development of new and specific fluorescent dyes for visualization of mitochondrial dynamics in living cells have facilitated the newfound interest in these fascinating organelles, which are now implicated in diverse cellular functions crucial in health and disease. Mitochondria play crucial roles in several age‐related diseases, and in the physiology of normal aging. In this review, we discuss the structural and functional aspects of mitochondria and their implications to the aging process, as well as its significance to skin aging. Available information on active molecules that can impact the mitochondrial functions, and their potential use in skin care products is also discussed, highlighting these organelles as a new focus for anti‐aging strategies in personal care.     

Travelers’ tropical skin diseases: Challenges and interventions

Tropical regions receive a significant part of the traveling population. It is very important that health professionals are familiar with the main tropical skin diseases and able to advice patients appropriately. This article reviews the main tropical diseases of travelers, with an emphasis on diagnosis, management, and prevention. Among others, cutaneous larva migrans, myiasis, tungiasis, Chagas disease, Dengue fever, African trypanosomiasis, filariasis, and leishmaniasis are discussed. Increasing awareness among travelers and health care professionals can help reduce morbidity and mortality. Continued research on new drugs and vaccines is needed to reduce the risks of tropical diseases.     

Recent advances in pediatric infectious diseases and their impact on dermatology

The past five years have seen numerous advances in the field of pediatric infectious diseases, and many of these have a substantial impact on the practice of dermatology. We review some of these advances and discuss their implications on etiology, diagnosis, therapy and complications of some relatively common conditions. The etiologic agent of exanthum subitum (roseola infantum) has been clearly implicated as a herpesvirus-6. Although in the classically described situation high fever in a young child is followed by defervescence and rash, two new scenarios have been described associated with this virus. The first is fever without rash and the second is rash without fever. The etiologic agent of erythema infectiosum ("slapped cheek") has been shown to be a human parvovirus B19. The virus has also been associated with aplastic crises (in hemoglobinopathies), hydrops fetalis, and a syndrome of subacute arthralgias in women. The etiologic agent in cat-scratch disease has recently been shown to be a small pleomorphic bacillus that also can produce pyogenic granuloma-like lesions in patients with acquired immunodeficiency syndrome. The number of cases of congenital syphilis, particularly in large cities, is increasing tremendously. Many of these infants have received no prenatal care because of drug abuse problems in their parents. Finally, we describe the changing etiology of impetigo that is predominantly associated with Staphylococcus aureus. We further describe the growing resistance to erythromycin and several new erythromycin drug-drug interactions.     

Understanding the development of advanced wound care in the UK: Interdisciplinary perspectives on care,cure and innovation

George Winter's 1962 paper in Nature reported his observation that wounds in young pigs healed more quickly if covered rather than being left open to the air. This has been widely regarded as the starting point for ‘advanced wound care’ because it established the idea that a wound dressing could influence outcomes. This paper argues that key to understanding innovation is placing technological advances within their broader historical and sociological context. As in other areas of healthcare, the development of innovation in wound care can be seen as a multifaceted, uneven and contested process, not the simple invention and introduction of ‘advanced’ products and services. Innovation in this field takes place at the intersection of historical changes in industry, scientific medicine, medical technologies, health care service delivery and the demographic and domestic spheres. Stemming from interdisciplinary exploration funded by the Arts and Humanities Research Council, this paper presents a provocative argument that contemporary wound care in the UK has become something of a partnership between elite nurses and industry marketing, with important consequences for science and service users. Current challenges in wound care stem in large part from an emphasis on a biomedical model focused on products (albeit one not led by medics) at the expense of considering service design and a social or public health model of patient care.     

Facial and oral aspects of some venereal and tropical diseases

Diseases of the tropical areas include some venereal diseases, and they are still very prevalent in some countries; Brazil is one of them. Very few cases are originated in large cities, as Rio de Janeiro, but at the University Hospital of the Federal University of Rio de Janeiro we also see those patients who come from the interior of the State of Rio de Janeiro or from other states to seek medical care at better equipped hospitals for this type of investigation and therapy. Venereal and tropical dermatoses have many different cutaneous manifestations and may affect skin in several locations. The face is one of the affected areas especially when the disease has a predilection for cartilage, oral and/or nasal mucosa. Alterations observed on the skin of the face and on the mucosa of the mouth of some tropical diseases, such as leprosy, leishmaniasis, paracoccidioidomycosis, donovanosis, and syphilis, as they are observed in Brazil, are presented and discussed in this article.     

Tropical dermatology: viral tropical diseases

Viruses are important pathogens in tropical areas; most of them, especially the tropical hemorrhagic fevers, produce mucocutaneous manifestations. More than any other kind of pathogen, viruses have the possibility for being widespread, since they have a greater probability of mutation than do bacteria, can cross species barriers easily, and infect both human beings and animals in habitats with a great biodiversity. Tropical habitats also have been subject to major ecologic changes in the last few decades, exposing humans to direct contact with these viruses and allowing hemorrhagic fevers due to new emergent viruses such as flaviviruses, filoviruses, arenaviruses, and hantaviruses to become major threats to public health. The collapse of eradication programs in many countries, as well as population increases and ecologic modifications, have led to the spread of dengue and yellow fever to large portions of the world owing to the dissemination of vectors, especially mosquitoes, with broad ecologic ranges. Viruses previously restricted to some geographic areas, such as Rift Valley fever, Crimean-Congo hemorrhagic fever, West Nile fever, and monkeypox are now affecting new countries and populations. Other viruses such as herpes B infection often affect travelers and animal handlers in most parts of the world. Dermatologic lesions occur in all these diseases and can facilitate a rapid diagnosis, leading to control of the virus and helping prevent possible outbreaks.     

Melanoma yield, number of biopsies and missed melanomas in a British teaching hospital pigmented lesion clinic: a 9-year retrospective study

The demand for pigmented lesion clinics (PLCs) is increasing in view of improved skin cancer awareness following public health education campaigns. These clinics offer an effective way of screening a large number of patients. However, there is no evidence, as yet, that they have an impact on mortality due to malignant melanoma. With the lack of follow-up inherent to these busy screening clinics, there is some concern that melanomas may be missed. This study reports on 7874 patient visits to a PLC in a teaching hospital between 1985 and 1994. In total, 1705 biopsies were performed over the 9-year period. Lesions were more likely to be biopsied in men compared with women. The yield for picking melanomas was one in 36 patient visits. The mean age of patients attending the PLC was 10 years less than the mean age for population-based melanomas. Melanoma thickness did not significantly change over the 9-year period. Only 0.2% of patients (14 cases) re-presented to the PLC for a second or third visit with a final diagnosis of melanoma, but for five of these patients, the interval between the two visits was over 2 years. Most of these 're-attending' melanomas were early lesions. PLCs offer a fast, safe and efficient service for the screening of pigmented lesions but their role in reducing mortality due to malignant melanoma remains to be established. It is likely that these clinics have an important role in terms of public health education regarding sun avoidance and early recognition of skin cancer.     

Bisexuality,Minority Stress,and Health

Purpose of Review

Bisexual individuals are at increased risk for negative health outcomes compared to heterosexual individuals and often compared to gay/lesbian individuals as well. The goal of this article is to summarize the current evidence-base on bisexual health disparities, to describe factors that influence them, and to review interventions designed to improve the health of bisexual individuals.

Recent Findings

Based on our review of the literature, we conclude that there is strong evidence that bisexual individuals are at increased risk for mental health and substance use problems. These disparities are evident across dimensions of bisexuality (identity, attraction, and behavior), but there are important nuances to these findings. There is also evidence that bisexual men are at increased risk for sexually transmitted infections (STIs) compared to heterosexual men and that bisexual women are at increased risk for STIs compared to both lesbians and heterosexual women. Although there are numerous causes of these disparities, a leading contributor is stress related to stigma and discrimination. Most of the interventions that have been developed for bisexual individuals are HIV prevention programs for behaviorally bisexual men of color. Despite less attention to mental health and substance use interventions for bisexual individuals, recent developments show promise in their potential application to this population.

Summary

Bisexual individuals are at increased risk for mental health, substance use, and sexual health problems, and this is due, in part, to stigma and discrimination. Future research should continue to examine how different dimensions of bisexuality relate to health disparities and factors that influence them. There is also an urgent need to develop, test, and disseminate interventions to improve the health of bisexual individuals..

     

Target proteins in inherited and acquired blistering skin disorders

Maintenance of an intact epidermis depends on secure adhesion between adjacent keratinocytes, and between basal keratinocytes and the underlying epidermal basement membrane. The major adhesion units that achieve this are the hemidesmosomes and desmosomes, but when these structures are disrupted, e.g., by gene mutations or autoantibodies, the resilience of the epidermis is lost and blisters develop. Recently, there have been considerable advances in our knowledge of the proteins and glycoproteins that contribute to maintaining keratinocyte adhesion via hemidesmosomes and desmosomes, as well as new insights into the molecular pathogenesis of several inherited and autoimmune blistering skin diseases. These new basic scientific data are clinically relevant, helping to improve patient management and to provide a rationale for developing better and more specific treatments for patients with inherited or acquired blistering skin diseases. In addition, there have also been improvements in our understanding of the organization and assembly of these adhesion structures, and their involvement in signalling pathways, intricately linked to skin development, wound healing and tumour invasion. This review provides an update on the structure and organization of hemidesmosomes and desmosomes, and on the molecular pathology of their various components that result in bullous skin diseases.     

Treatment of New World cutaneous leishmaniasis--a systematic review with a meta-analysis

Background New World leishmaniasis is an important endemic disease and public health problem in developing countries. The increase in ecologic tourism has extended this problem to developed countries. Few drugs have emerged over the past 50 years, and drug resistance has increased, such that the cure rate is no better than 80% in large studies. Despite these data, there has been no systematic review with a meta‐analysis of the therapy used in this important tropical disease. The aim of this study was to determine the best drug management in the treatment of cutaneous leishmaniasis (CL) in Latin America based on the best studies published in the medical literature. Methods MEDLINE, LILACS, EMBASE, Web of Science, and Cochrane Library databases were searched to identify articles related to CL and therapy. Articles with adequate data on cure and treatment failure, internal and external validity information, and more than four patients in each treatment arm were included. Results Fifty‐four articles met our inclusion criteria and 12 were included in the meta‐analysis. Pentavalent antimonials were the most studied drugs, with a total of 1150 patients, achieving a cure rate of 76.5%. The cure rate of pentamidine was similar to that of pentavalent antimonials. Other drugs showed variable results, and all demonstrated an inferior response. Conclusion Although pentavalent antimonials are the drugs of choice in the treatment of CL, pentamidine showed similar results. Nevertheless, several aspects, such as cost, adverse effects, local experience, and availability of drugs to treat CL, must be considered when determining the best management of this disease, especially in developing countries where resources are scarce.