Key Points Tapeworms cause disease in humans in either of the two stages of their life cycle: the adult stage, which takes place in the intestines, where it causes mild or non-existent clinical manifestations, and the larval stage, which causes signs and symptoms secondary to enlarging larval cysts in various tissues of a mammalian host. Besides Taenia solium and Echinococcus granulosus , cutaneous disease by cestodes…
Introduction Nematodal Helminths Nematodal helminths represent infectious agents that are not very infectious, but have developed a delicate strategy to infect human hosts. As such, they manage to overcome the epidermal barrier, enter the human body, and travel by several methods to different places in the body, where they cause disease. These diseases are endemic in Asia, Africa, and Latin America. Despite the existence of effective…
Filariasis Sam Kalungi Lynnette Tumwine Key Points The filariases result from infection with insect-vector-borne tissue-dwelling nematodes. This group of nematodes is characterized by having a microfilaria stage of development between the egg and the fully developed larva. Depending on the species, adult filariae may live in the lymphatics, blood vessels, skin, connective tissues, or serous membranes. The females produce larvae (microfilariae) that live in the blood stream or…
Key Points Free living amebas infection is a CNS disease, mostly fatal, that commonly may present first with a characteristic cutaneous lesion. A history of exposure to soil or water is common. The cutaneous lesion may precede CNS involvement for months. The classical lesion is an asymptomatic plaque, most commonly located on the central face, but also on the extremities (knee area) or else. The histology…
Key Points The leishmaniases are a group of zoonotic infections of humans and certain animals caused by several species of a flagellated parasite belonging to the order Kinetoplastidae, genus Leishmania , and transmitted by the bite of a fly of the genera Phlebotomus and Lutzomyia . Humans, dogs, and rodents are the main reservoirs for the Leishmania microorganisms. Cure of leishmaniases would be related to a…
Key Points Also known as sleeping sickness, African trypanosomiasis is an acute and chronic disease caused by a parasite called Trypanosoma brucei , which is transmitted by the tsetse flies. Recent travel to endemic areas of Africa should lead physicians to consider African trypanosomiasis in individuals presenting with acute febrile illnesses. The three most specific signs include the chancre (first stage), the targetoid macular trypanid (second…
Key Points Preparation is everything. Study the history and culture of the area where you will be working. Refresh your knowledge of the local spectrum of disease. Find out what is locally available in the way of medical personnel, facilities, and pharmaceuticals. Aim to be as self-contained as possible (personal and medical requirements) so as not to impose a burden on the local system. Cultural Context…
Key Points Among travelers to developing countries, both tropical and non-tropical diseases are commonly reported problems and most of these are self-limited illnesses such as diarrhea, respiratory infections, and skin disorders. Of the non-tropical diseases, dermatosis including cutaneous larva migrans, insect bites, and bacterial infections are the most frequent skin problems in ill travelers who seek medical care. Physicians with patients who travel should be familiar…
Introduction With increasing numbers of persons from industrialized, temperate countries traveling and / or working in tropical lands, there is a marked need for physicians to be able to diagnose accurately and treat tropical diseases with mucocutaneous manifestations. While some studies demonstrate that approximately one-third to two-thirds of travelers returning from tropical countries experience some health problem, diarrhea is the most prevalent complaint. Mucocutaneous problems, however, are among…
Evidence Levels: A Double-blind study B Clinical trial ≥ 20 subjects C Clinical trial < 20 subjects D Series ≥ 5 subjects E Anecdotal case reports Open full size image Yellow nails are the main clinical manifestation (88% of cases) leading to yellow nail syndrome (YNS) diagnosis. Xanthonychia is unsightly and varies from pale yellow to a more or less dark and greenish color. The nail…
Evidence Levels: A Double-blind study B Clinical trial ≥ 20 subjects C Clinical trial < 20 subjects D Series ≥ 5 subjects E Anecdotal case reports Open full size image Xerosis is the term used to describe a condition where there is a rough, dry, textural feel to the skin, accompanied by fine scaling and sometimes fine fissuring. Increasing xerosis is usually accompanied by increasing itch.…
Acknowledgment This research was supported by the Intramural Research Program of the NIH, National Cancer Institute, Center for Cancer Research. Evidence Levels: A Double-blind study B Clinical trial ≥ 20 subjects C Clinical trial < 20 subjects D Series ≥ 5 subjects E Anecdotal case reports Open full size image Xeroderma pigmentosum (XP) is a rare autosomal recessive disorder characterized by cellular hypersensitivity to the damaging…
Evidence Levels: A Double-blind study B Clinical trial ≥ 20 subjects C Clinical trial < 20 subjects D Series ≥ 5 subjects E Anecdotal case reports Open full size image Xanthomas are flat, yellow plaques or nodules consisting of abnormal lipid deposits. Clinically, xanthomas are classified as eruptive, tuberoeruptive, tuberous, tendinous, verruciform, or plane. Plane xanthomas are the most common and include xanthelasma palpebrarum, xanthoma striatum…
Evidence Levels: A Double-blind study B Clinical trial ≥ 20 subjects C Clinical trial < 20 subjects D Series ≥ 5 subjects E Anecdotal case reports Open full size image Wells syndrome (eosinophilic cellulitis) is a rare inflammatory disorder resembling a bacterial cellulitis. Patients are often treated with antibiotics and fail to respond before the diagnosis of Wells syndrome is considered and then confirmed on skin…
Evidence Levels: A Double-blind study B Clinical trial ≥ 20 subjects C Clinical trial < 20 subjects D Series ≥ 5 subjects E Anecdotal case reports Open full size image Warts are a common disease caused by infection with various strains of the human papillomavirus (HPV). They appear on different sites of the body and in various forms, including common, flat, filiform, periungual, plantar, mosaic, and…
Evidence Levels: A Double-blind study B Clinical trial ≥ 20 subjects C Clinical trial < 20 subjects D Series ≥ 5 subjects E Anecdotal case reports Open full size image Introduction Vulvodynia has been defined by the International Society for the Study of Vulvovaginal Disease (ISSVD) as vulval discomfort, most often described as a burning pain, occurring in the absence of relevant visible findings or a…
Evidence Levels: A Double-blind study B Clinical trial ≥ 20 subjects C Clinical trial < 20 subjects D Series ≥ 5 subjects E Anecdotal case reports Open full size image Vitiligo is a common autoimmune disease of the skin resulting from the destruction of epidermal melanocytes by cytotoxic CD8+ T cells. It presents with multiple white macules and patches, which can significantly affect patients’ self-esteem and…
Evidence Levels: A Double-blind study B Clinical trial ≥ 20 subjects C Clinical trial < 20 subjects D Series ≥ 5 subjects E Anecdotal case reports Open full size image Rubella Rubella (German measles, 3-day measles) is caused by a member of the Togaviridae family; it is a usually benign infection characterized by a short prodrome of fever, cervical, suboccipital or postauricular lymphadenopathies and arthralgias, followed…
Evidence Levels: A Double-blind study B Clinical trial ≥ 20 subjects C Clinical trial < 20 subjects D Series ≥ 5 subjects E Anecdotal case reports Open full size image Varicella (chickenpox) is a self-limited viral exanthem caused by primary infection with varicella zoster virus (VZV), a double-stranded DNA herpesvirus. Varicella is a highly communicable disease transmitted through respiratory droplets and/or direct contact with vesicular fluid.…
Evidence Levels: A Double-blind study B Clinical trial ≥ 20 subjects C Clinical trial < 20 subjects D Series ≥ 5 subjects E Anecdotal case reports Open full size image Open full size image Urticaria is a frequent disease affecting up to 20% of us at least once during our lifetime. The hallmark feature of urticaria is the wheal, which is caused by mast cell–derived mediators…