Imported tropical diseases

Imported tropical diseases are among the top three leading causes for morbidity and may affect up to 8% of returning travelers. Because the spectrum of dermatological manifestations seen in travelers is broad, it can be challenging for physicians to recognize and treat such conditions in a timely and efficient manner. Therefore, the present review highlights common imported tropical diseases with a focus on treatment regimens. Specifically, cutaneous larva migrans, myiasis, swimmer's itch, mycetoma, Chagas disease, and leishmaniasis are discussed. As awareness increases among travelers, immigrants, and health care providers regarding imported tropical diseases, early intervention and proper diagnosis can ensue, thus reducing morbidity and mortality in affected individuals.     

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.     

Vacation and tropical dermatoses

Besides fever and diarrhea, skin diseases are the third most common cause of morbidity in returning travelers after a stay in a tropical country. Approximately one- quarter of these dermatological symptoms can be referred to a classical tropical disease. The majority are of infectious origin. Often only the clinical appearance leads to the diagnosis of a tropical disease as myiasis, cutaneous larva migrans, tungiasis or cutaneous leishmaniasis. Not infrequently the dermatological symptoms lead to the diagnosis of a primarily systemic tropical disease. For example, an eschar with or without a rash might lead to the diagnosis of a South African tick bite fever caused by Rickettsia africae days before serology may turn positive. Less common tropical skin diseases such as lymphatic filariasis and loiasis need to be considered in returning long-term travelers and immigrants.     

Tropical Skin Diseases in Children: A Review— Part I

Because of travel and migration patterns, tropical skin diseases are now seen all around the world, not just in tropical or developing countries. Nutrition, housing, and environmental factors play an important role in these infectious diseases, so when they appear out of their normal environments, their classic presentation may vary. Tropical diseases can also present differently in childhood, making their recognition, diagnosis, and management a clinical challenge. Health care providers in developed countries need to be familiar with tropical skin diseases and be able to diagnose them in returning travelers or immigrants in order to optimize care. This article aims to review the epidemiologic, clinical, diagnostic, and therapeutic aspects of some of the most common tropical dermatologic conditions in children.     

Imported Tropical Infectious Ulcers in Travelers

Skin ulcers are a commonly encountered problem at departments of tropical dermatology in the Western world. Furthermore, the general dermatologist is likely to be consulted more often for imported chronic skin ulcers because of the ever-increasing travel to and from tropical countries. The most common cause of chronic ulceration throughout the world is probably pyoderma. However, in some parts of the world, cutaneous leishmaniasis is one of the most prevalent causes. Mycobacterium ulcerans is an important cause of chronic ulcers in West Africa. Bacterial infections include pyoderma, mycobacterial infections, diphtheria, and anthrax. Pyoderma is caused by Staphylococcus aureus and/or beta-hemolytic streptococci group A. This condition is a common cause of ulcerative skin lesions in tropical countries and is often encountered as a secondary infection in travelers. The diagnosis is often made on clinical grounds. Antibacterial treatment for pyoderma should preferably be based on culture outcome. Floxacillin is generally active against S. aureus and beta-hemolytic streptococci. Infection with Mycobacterium ulcerans, M. marinum, and M. tuberculosis may cause ulcers. Buruli ulcers, which are caused by M. ulcerans, are endemic in foci in West Africa and have been reported as an imported disease in the Western world. Treatment is generally surgical, although a combination of rifampin (rifampicin) and streptomycin may be effective in the early stage. M. marinum causes occasional ulcerating lesions in humans. Treatment regimens consist of combinations containing clarithromycin, rifampin, or ethambutol. Cutaneous tuberculosis is rare in travelers but may be encountered in immigrants from developing countries. Treatment is with multiple drug regimens consisting of isoniazid, ethambutol, pyrazinamide, and rifampin. Cutaneous diphtheria is still endemic in many tropical countries. Cutaneous diphtheria ulcers are nonspecific and erythromycin and penicillin are both effective antibacterials. Antitoxin should be administered intramuscularly in suspected cases. Anthrax is caused by spore-forming Bacillus anthracis. This infection is still endemic in many tropical countries. Eschar formation, which sloughs and leaves behind a shallow ulcer at the site of inoculation, characterizes cutaneous anthrax. Penicillin and doxycycline are effective antibacterials. Cutaneous leishmaniasis is caused by different species belonging to the genus Leishmania. The disorder is one of the ten most frequent causes of skin diseases in travelers returning from (sub)tropical countries. The clinical picture is diverse, ranging from a painless papule or nodule to an ulcer with or without a scab. Treatment depends on the clinical manifestations and the species involved.Sporotrichosis, chromo(blasto)mycosis, and mycetoma are the most common mycoses that may be accompanied by ulceration. Infections are restricted to certain regions and often result from direct penetration of the fungus into the skin. Anti-mycotic treatment depends on the microorganism involved. The most common causes of infectious skin ulceration encountered in patients from tropical countries who present at a department of tropical dermatology are reviewed in this article.     

Life-threatening dermatoses in travelers

Life-threatening dermatoses in travelers relates to infections, or allergic or drug reactions. Of the infectious dermatoses, most are parasitic or viral- because of the short time frame. Bacterial infections usually have a longer incubation. More significant are allergic reactions from environmental or dietary causes, and drug reactions, especially those drugs taken for prophylaxis from tropical diseases. All of these can be fulminant and therefore an awareness and early therapeutic intervention is mandatory.     

Microcirculatory changes in travelers to a tropical country

BACKGROUND: Travelers to tropical areas seem to be affected by nonhealing leg ulcers more frequently. One of the factors that can affect wound healing in a negative manner is leg edema. This study was performed to determine whether there is increased leg edema in travelers to tropical areas. METHOD: In this study, we measured the capillary filtration rate (CFR) of the lower leg by strain gauge plethysmography, as a measure of leg edema, on location in Surinam. Three groups were included: A, travelers in the first few weeks after arrival; B, travelers who had stayed in the tropics for a minimum of 2 months; C, native inhabitants. RESULTS: The mean CFR (mL/100 mL tissue/min) was significantly higher in group A than in groups B and C; the difference between groups B and C was not significant (group A 0.05 mL/100 mL tissue/min (standard deviation (SD), 0.03) vs. group B 0.02 mL/100 mL tissue/min (SD, 0.02), P = 0.01, and vs. group C 0.02 mL/100 mL tissue/min (SD, 0.02), P = 0.01). CONCLUSIONS: Travelers to tropical areas are affected by increased CFR in the first few weeks after arrival. A prolonged stay leads to the normalization of the CFR. Compression therapy is recommended for travelers to the tropics.     

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.     

Imported skin diseases in dermatology.

Millions of afflicted people suffer from conditions which Japanese dermatologists may rarely encounter. Many of our patients travel extensively either as part of work-related business trips or during vacationing. From three to ten percent of travelers experience skin, hair or nail disorders. With worldwide travel heightening exposure to the causative agents, there is an increasing likelihood that a patient with leishmaniasis, Boutonneuse fever, onchocerciasis, loaiasis, dengue fever, cutaneous larva migrans or other recently acquired skin conditions from a far away land will visit your office for diagnosis and treatment. The clinical characteristics, diagnostic tests and therapeutic options for such imported tropical diseases will be discussed.     

Skin diseases reported by workers from UNESP campus at Rubi?o Jr, Botucatu-SP (Brazil)

There are few populational studies to estimate the dimension of dermatological diseases. We performed a survey with 515 employees from UNESP campus, Botucatu (SP), exploring demographic data, medical appointments and dermatological diagnoses. Additionally, we induced questions about prevalent diseases. Appointments to the dermatologist were reported by 77% of subjects. The main dermatoses spontaneously reported were mycoses, allergies, nevi and viral warts. There were association of juvenile acne and males (OR=2.3), melasma and females (OR=8.0), and onychomycosis with older age (OR=1.05). Surveys are important to know the demand for dermatology care, besides directing formulation of public health policy and medical education.     

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.     

Skin diseases in Bamako (Mali)

Background Skin diseases have only recently been considered as a possible public health problem in developing countries. Data supporting this matter are scarce. The aim of this study is to report the experience of a specialized dermatologic center in Bamako (Mali) in order to complete two previous studies conducted in the Bamako area: a prevalence study in the general population and a study in nonspecialized health centers of Bamako. It is our intention to provide a comprehensive picture of the problem of skin diseases in an African developing country. Methods We retrospectively collected all cases of skin diseases diagnosed during consultations provided at the Institut Marchoux in Bamako, the only center specializing in dermatology in Mali, during the year 1993. Results A total of 10,575 new outpatients were seen with 10,889 skin diseases. The main skin diseases registered were as follows: infectious dermatoses (41% of all diagnoses, including scabies (16.6%), superficial mycoses (13.6%), and primary pyoderma (5.6%)), dermatitis (20.4%), papular urticaria (4.4%), acne (4.2%), pityriasis alba (3.6%), keratoderma (3.6%), and urticaria (3%). Typical tropical infectious diseases accounted for only 1% of all diagnoses. Conclusions It appears that certain skin diseases (mainly scabies and pyoderma) are an important health problem for the population of the Bamako area. Public health policies should be implemented in order to manage this problem rationally.     

Cutaneous manifestations of bartonellosis

Bartonellosis are diseases caused by any kind of Bartonella species. The infection manifests as asymptomatic bacteremia to potentially fatal disorders. Many species are pathogenic to humans, but three are responsible for most clinical symptoms: Bartonella bacilliformis, Bartonella quintana, and Bartonella henselae. Peruvian wart, caused by B. bacilliformis, may be indistinguishable from bacillary angiomatosis caused by the other two species. Other cutaneous manifestations include maculo-papular rash in trench fever, papules or nodules in cat scratch disease, and vasculitis (often associated with endocarditis). In addition, febrile morbilliform rash, purpura, urticaria, erythema nodosum, erythema multiforme, erythema marginatus, granuloma annularis, leukocytoclastic vasculitis, granulomatous reactions, and angioproliferative reactions may occur. Considering the broad spectrum of infection and the potential complications associated with Bartonella spp., the infection should be considered by physicians more frequently among the differential diagnoses of idiopathic conditions. Health professionals and researchers often neglected this diseases.     

Skin diseases in children in rural Kenya: long-term results of a dermatology project within the primary health care system

BACKGROUND: Following an epidemiological study on skin diseases in 5780 pupils from 13 schools in rural western Kenya in 1993, a dermatology project within the primary health care system was established in 1994 by the German non-government organization (NGO) 'Doctors in Aid of Children with Skin Diseases in Africa'. Within this project trained community health workers carried out regular visits to schools and nurseries and treated children with hydrocortisone acetate 1% cream for dermatitis, gentian violet 1% solution for bacterial skin infections, Whitfield's ointment for dermatophytoses and benzylbenzoate emulsion 25% for scabies. OBJECTIVES: To assess the impact of this intervention. METHODS: In 1999, after a 5-year period, 4961 pupils from the same 13 schools were re-examined and the prevalence rates were compared. RESULTS: Non-infective dermatitis had a prevalence of 1.7% in 1993 as well as in 1999; among the communicable diseases bacterial infections declined from 12.7% to 11.3% (not significant), fungal infections rose from 10.1% to 13.9% (P < 0.05) and arthropod infections (mainly scabies) remained at similar levels of 8.3% in 1993 and 8.0% in 1999. A distinctive reduction could only be found for tropical ulcers (0.1% in 1999 compared with 1.2% in 1993). CONCLUSIONS: The prevalence of dermatoses in children in rural Africa does not only depend on treatment schemes within the primary health care system, but on the socio-economic conditions available.     

Scabies and pyodermas – diagnosis and treatment

Scabies and pyodermas are two of the commonest skin infections in tropical settings. They affect large numbers of people, particularly children, and account for a large burden of disease for peripheral health care teams. Despite this there have been significant advances in our knowledge of these diseases, their impact and their management. However there is a need to evaluate these developments in this specific setting, tropical health and in the context of communities with limited resources. This section will describe these advances and the challenges that remain.     

Dermatobia hominis: Small Migrants Hidden in Your Skin

Myiasis is a parasitic infestation of vertebrate animal tissues due to maggots of two-winged flies (Diptera) that feed on living or necrotic tissue. Dermatobia hominis occurs widely in tropical parts of Latin America; it is the most common cause of furuncular myiasis in this region. The continuous increase in international travel has increased the possibility of observing this pathology outside endemic countries, especially in travelers returning from the tropics. If clinicians are aware of the possibility of the disease and its treatment options, this dermatosis can be easily managed. However, diagnostic delay is very common because the disease is often misdiagnosed as a bacterial skin infection. Here, we report 2 cases of furuncular myiasis caused by D. hominis in travelers returning to Italy from Latin America. Surgical and noninvasive treatment approaches are also described.     

Revisiting Buruli ulcer

Buruli ulcer (BU), or Mycobacterium ulcerans infection, is a new emerging infectious disease which has been reported in over 33 countries worldwide. It has been noted not only in tropical areas, such as West Africa where it is most endemic, but also in moderate non‐tropical climate areas, including Australia and Japan. Clinical presentation starts with a papule, nodule, plaque or edematous form which eventually leads to extensive skin ulceration. It can affect all age groups, but especially children aged between 5 and 15 years in West Africa. Multiple‐antibiotic treatment has proven effective, and with surgical intervention at times of severity, it is curable. However, if diagnosis and treatment is delayed, those affected may be left with life‐long disabilities. The disease is not yet fully understood, including its route of transmission and pathogenesis. However, due to recent research, several important features of the disease are now being elucidated. Notably, there may be undiagnosed cases in other parts of the world where BU has not yet been reported. Japan exemplifies the finding that awareness among dermatologists plays a key role in BU case detection. So, what about in other countries where a case of BU has never been diagnosed and there is no awareness of the disease among the population or, more importantly, among health professionals? This article will revisit BU, reviewing clinical features as well as the most recent epidemiological and scientific findings of the disease, to raise awareness of BU among dermatologists worldwide.     

故事引导法和互动参与法在性病艾滋病教育教学中的应用

本文分析社会尤其是年轻人性认知的变化特征，探讨在性教育及性病艾滋病教育教学方面存在的问题，提出应充分利用医学院校性病艾滋病教育作为切入点，培训医学生及医务人员作为教育培训的主力军。作者结合自身的教学实践经验，总结提炼出了以病例故事作为教学特点的故事引导法和以头脑风暴、互动游戏、角色扮演、分组讨论等为形式的互动交流法两种教学方法，在性病艾滋病教育教学中获得了良好的实践效果。