Changing paradigms in parasitic infections: common dermatological helminthic infections and cutaneous myiasis

Tropical parasitic itch in returned travellers and immigrants from endemic areas

Itch is the most common skin symptom among tropical parasitic diseases (TPD), but there are limited data about its characteristics in these conditions. In dermatology practices and travellers' health clinics in the developed world, itch is a common complaint among travellers returning from endemic areas, as well among migrants arriving from endemic areas, where they may have been exposed to TPD. Studying aspects of pruritus among TPD may lead to improvements in prompt, accurate diagnosis and management of these conditions. This review examines the major itch-inducing TPDs, including schistosomiasis, echinococcosis, onchocerciasis, scabies, cutaneous larva migrans, larva currens, African trypanosomiasis, dracunculiasis and other causes of travel associated pruritus. We focus on the link between pruritus and other symptoms, aetiology, clinical staging and therapeutic options for these parasitic illnesses. Because some tropical parasitic diseases can present with significant pruritus, we attempt to identify aspects of the pruritus that are characteristic of-or unique to-specific conditions. These diagnostic insights may help clinicians create a rational and focused differential diagnosis and help determine optimal disease management pathways. In this sense, management involves treating the individual, seeking epidemiologically linked cases, preventing recurrences or relapses, and reducing spread of the disease.

Human myiasis cases originating and reported in africa for the last two decades (1998-2018): A review

The article reviews literature on myiasis in Africa and cases that originated in Africa over the last two decades (1998-2018). The relevant literature was obtained by using several databases (Science-Direct, JSTOR, Google Scholar, Ebscohost and PubMed). We searched for the following words or their combination myiasis, maggots, fly species responsible for myiasis found in Africa, and the different types of myiasis. References in several articles provided links to other relevant works. Only papers written in English were reviewed. In total, we reviewed 51 articles which covered a total of 849 myiasis cases. The review encompasses geographical distribution of the disease, dipteran species responsible, predisposing factors, sex of the patient, type of myiasis and treatment. Myiasis is found in most parts of the African continent, however only 18 articles reported myiasis cases in Africa during the period under review. The rest of the articles report cases from the rest of the world but acquired by travellers when visiting Africa. Cordylobia anthropophaga (Blanchard) was responsible for 93.28% of all the reported cases in this review. The low number of articles on human myiasis reported in Africa may be due to underreporting by physicians or most cases are not diagnosed. Therefore, the actual prevalence of myiasis in Africa is currently unknown.

Infectious differential diagnosis of chronic generalized pruritus without primary cutaneous lesions: a review of the literature

Pruritus is one of the most common complaints among patients referred to a dermatology clinic. "Chronic generalized pruritus" is described as the sensation of itching on the entire body surface, which lasts at least 6 or more weeks. This symptom can be a disabling phenomenon for patients and may sometimes interfere with daily activities such as sleep. If specific dermatological findings are observed, the physician easily comes to a diagnosis and treats the condition, whereas, when primary lesions are not detected, the diagnosis can become challenging, and some patients have to undergo extensive evaluations. The association between some systemic disorders and chronic generalized pruritus is widely known and confirmed. Many infections have been associated with pruritus, but few are considered to cause chronic generalized pruritus without any characteristic skin lesions. We aimed to gather all the available data on infectious causes of chronic generalized pruritus with no diagnostic cutaneous lesions to assist fellow physicians in the process of evaluation of these challenging cases.

[Urological infections and migration]

In the context of refugee migrations infectious diseases are being more frequently diagnosed, which the responsible physicians as well as urologists have never seen before. This is due to the poorer health and hygiene conditions in the country of origin, during the flight and in the refugee camps. In Europe increasing incidences of tuberculosis, schistosomiasis and scabies have recently been observed. Tuberculosis and schistosomiasis are often accompanied by unspecific symptoms or can resemble normally encountered urological diseases. Due to the highly contagious nature of scabies, a screening of new arrivals is recommended. A timely differential diagnostic inclusion of these disease patterns is enormously important. Despite the reduction in the numbers of asylum applications in Germany, a higher number of unregistered migrants is generally assumed, who also elude the healthcare system and can therefore contribute to the spread of these rare infectious diseases.

Cutaneous Manifestations of Selected Parasitic Infections in Western Pacific and Southeast Asian Regions

Cutaneous manifestations of parasitic infections often result in discomfort, debilitation, and even stigmatization. Data on cutaneous manifestations of parasitic infections, however, are limited. This article provides updates on the cutaneous manifestations of parasitic infections which are known to occur in Western Pacific and Southeast Asian regions, such as scabies, pediculosis, cutaneous larva migrans, larva currens, cutaneous schistosomiasis, cutaneous enterobiasis, cutaneous cysticercosis, acute dermatolymphangioadenitis (lymphatic filariasis), and cutaneous amoebiasis. The lack of epidemiological data on these conditions suggests the need for improvements in recording and reporting of cases. Utilization of advance diagnostic modalities and capacity building of health workers are important for proper case management. Cutaneous manifestations of parasitic infections are a topic rarely studied and thus represent an opportunity for further research.

Cutaneous Myiasis

Myiasis is defined as the infestation of live vertebrates, either humans or animals, with dipterous larvae. Many organs can be infested by these larvae with cutaneous myiasis being the most common form. Cutaneous myiasis can be divided into three categories: localized furuncular myiasis, migratory myiaisis and wound myiasis, which occurs when fly larvae infest the open wounds of the host. Human myiasis has worldwide distribution, with more species and a heavier burden in tropical and subtropical countries. In recent years with increased travel to the tropics, myiasis has become common in returning travelers from these regions, Furuncular myiasis, mainly Dermatobia homonis becomes the most common form seen among them. Treatment is based on full extraction of the larva and no antibiotic treatment is needed. Understanding the mode of transmission of each type of myiasis may help to prevent the infestation.

Periungual myiasis caused by wohlfahrtia magnifica mimicking an ingrown toenail

Myiasis is the infestation of organs and tissues of human being or other vertebrate animals with dipterous larvae. Myiasis is generally rare in humans, especially in children. We present the first case of periungual myiasis by Wohlfahrtia magnifica in a 5-year-old female. Wohlfahrtia magnifica is an obligatory parasite, which has been described as cause of ophthalmomyiasis, otomyiasis, oral myiasis, vulvar myiasis and wound myiasis. Treatment of myiasis and ingrown toenail is generally non-operative although both entities can be serious and/or non-responsive to conservative therapy.

Pulmonary Hemorrhage Secondary to Disseminated Strongyloidiasis in a Patient with Systemic Lupus Erythematosus

Introduction. Pulmonary hemorrhage secondary to disseminated strongyloidiasis is an unusual, well-recognized entity in immunocompromised patients with autoimmune disease, which is associated with the hyperinfection syndrome, sepsis, and a high mortality rate. Case Presentation. We present a case of a 44-year-old Mexican woman with systemic lupus erythematosus and acute bacterial meningitis who developed pulmonary hemorrhage with acute respiratory failure requiring mechanical ventilation, treated with broad spectrum systemic antibiotics and high dose methylprednisolone, who subsequently developed a characteristic purpuric skin eruption and septic shock and died two days later of refractory hypoxemia caused by massive pulmonary bleeding. The postmortem examination reports filariform larvae of S. stercolaris in lung, skin, and other organs. Conclusion. This case highlights the importance of considering disseminated strongyloidiasis in the differential diagnosis of diffuse alveolar hemorrhage in systemic lupus erythematosus, and screening for S. stercolaris infection before initiation of immunosuppressive therapy should be considered, especially in endemic areas. Disseminated strongyloidiasis has a high mortality rate, explained in part by absence of clinical suspicion.

Case of human Dirofilaria repens infection manifested by cutaneous larva migrans syndrome

Dirofilaria repens, parasite of subcutaneous tissues of dogs and other carnivores, represents high infection risk for animals and humans in Europe. In men, infection usually presents as nodule in subcutaneous tissues or, less often, the lesions are localised around the eyes. The work presents first confirmed clinical case of human D. repens infection connected with cutaneous larva migrans syndrome. In patient, the migration of the worm caused true signs of creeping eruption, elevated sinuous track under the skin. It was connected with severe pain, burning and erythema of adjacent skin. Symptoms appeared at least three times, approximately once a month, always in the evening or night and lasted from several minutes to several days. In December 2014, during the scratching of residual pruritic lesion, patient removed 6-cm long, whitish worm from the wound. Morphological features (longitudinal ridges) and PCR amplification of cytochrome oxidase subunit 1 (CO1) confirmed Dirofilaria repens as etiological agent of infection. Herein, presented case confirmed that D. repens infection in humans can be associated with real creeping eruption, clinical sign of cutaneous larva migrans and should be included in its differential diagnosis.

Oral helminthic infestations

Oral infections caused by helminths (worms) are rarely encountered in clinical practice, and consequently, there is a paucity of information in the medical and dental literature about these conditions. In the present article, we review the English literature related to oral helminthic infestations. The main oral infections caused by helminths include four roundworm (trichinosis, trichuriasis, filariasis, and larva migrans) and three tapeworm infections (cysticercosis, sparganosis, and echinococcosis). Cases are mainly encountered in endemic areas and mainly present a benign clinical picture. The diagnosis of oral helminthic infections is mostly established after histopathological examination, which shows parasitic larvae lined by fibrous tissue and inflammatory cells. Surgical excision is the preferred treatment of isolated oral lesions caused by helminths; however, patients should undergo thorough medical evaluation to exclude the possible involvement of other body systems.

[Antibiotic resistant furuncles: think myiasis]

Les myiases sont des infections parasitaires par des larves de mouches. La localisation cutanée doit être évoquée de retour d'un pays tropical devant une évolution inhabituelle de lésions cutanées. Nous rapportons une observation d'un militaire tunisien, ayant séjourné en République Démocratique du Congo. Il était atteint de myiase cutanée simulatrice d'une furonculose résistante aux antibiotiques. L'intérêt de cette observation est de souligner l'importance d’évoquer la myiase dont le traitement est simple et rapide chez un patient de retour de zone d'endémie.

Oral myiasis in two children

The term myiasis refers to growth of parasitic diptera in the living or dead tissue of vertebrate animal. Most cases of myiasis in humans are mild and rarely present in the mouth. We describe 2 children with severe oral myiasis that evolved to oral and maxillofacial mutilations. We discuss preventive measures.

Pathogenicity of Trichobilharzia spp. for Vertebrates

Bird schistosomes, besides being responsible for bird schistosomiasis, are known as causative agents of cercarial dermatitis. Cercarial dermatitis develops after repeated contact with cercariae, mainly of the genus Trichobilharzia, and was described as a type I, immediate hypersensitivity response, followed by a late phase reaction. The immune response is Th2 polarized. Primary infection leads to an inflammatory reaction that is insufficient to eliminate the schistosomes and schistosomula may continue its migration through the body of avian as well as mammalian hosts. However, reinfections of experimental mice revealed an immune reaction leading to destruction of the majority of schistosomula in the skin. Infection with the nasal schistosome Trichobilharzia regenti probably represents a higher health risk than infections with visceral schistosomes. After the skin penetration by the cercariae, parasites migrate via the peripheral nerves, spinal cord to the brain, and terminate their life cycle in the nasal mucosa of waterfowl where they lay eggs. T. regenti can also get over skin barrier and migrate to CNS of experimental mice. During heavy infections, neuroinfections of both birds and mammals lead to the development of a cellular immune response and axonal damage in the vicinity of the schistosomulum. Such infections are manifest by neuromotor disorders.

Myiasis

Myiasis is defined as the infestation of live vertebrates (humans and/or animals) with dipterous larvae. In mammals (including humans), dipterous larvae can feed on the host's living or dead tissue, liquid body substance, or ingested food and cause a broad range of infestations depending on the body location and the relationship of the larvae with the host. In this review, we deeply discuss myiasis as a worldwide infestation with different agents and with its broad scenario of clinical manifestations as well as diagnosis techniques and treatment.

Orofacial myiasis of the gingiva and nasal cavity: a report of two cases and general review

BACKGROUND

Infestation of the orofacial region with live maggots is a distressing condition and many clinicians are not aware of the existence of such an entity. Usually the condition affects individuals who are debilitated, mentally challenged, and physically not able to attend to their personal needs because of lack of psychomotor coordination.

METHODS

This article describes two cases of orofacial myiasis reported at a rural dental school in India. Removal of the live maggots, supportive treatment, management of the cases, and morphologic features of maggots are described.

RESULTS

Both the patients belonged to a low socioeconomic group and were physically and mentally challenged. Maggot removal improved the patients' pain and distress, and entomologic study identified the maggots as belonging to Chrysomya bezziana.

CONCLUSIONS

Oral myiasis is more prevalent than commonly believed to be and an astute practitioner should be aware of such maggots in the mouth, in cases of oral and maxillofacial trauma and in vulnerable categories of patients. These patients are not physically or mentally endowed to ward off flies or complain about worms burrowing their way into oral wounds. Occurrences of such cases are rare in developed countries and reflect the lack of special care for the vulnerable group of patients belonging to certain geographic areas.

Skin infections in developing countries

PURPOSE OF REVIEW

In developing countries, where the majority of people have a low income and live in resource-poor settings, skin infections are prevalent. Data from recent studies provide insight into the most common skin infections and their management.

RECENT FINDINGS

Several studies confirm that skin infections account for the majority of pediatric mortality and morbidity in developing countries. They are prevalent in resource-poor settings and rural areas in certain parts of the world. Also, hot, humid climates and overcrowding predispose to skin infections. Most of the skin infections are curable with effective medication.

SUMMARY

Skin infections are of particular importance in developing countries. This review focuses on the most common skin infections and summarizes the most recent knowledge on the epidemiology, morbidity, and treatment in resource-poor settings.

Cutaneous myiasis

Myiasis is the infestation of living tissue by the larvae of flies in the order Diptera. Cutaneous involvement is the most common type of myiasis. Cutaneous myiasis can be subdivided into furuncular, migratory, and wound myiasis. Each subtype is reviewed with discussion of the larvae involved, presenting signs and symptoms, clinical differential diagnoses, and treatment. Preventive measures are also described.

LEARNING OBJECTIVES

At the conclusion of this learning activity, participants should be familiar with the causal agents, clinical manifestations, and treatment of human cutaneous myiasis.

Cutaneous myiasis

Cutaneous myiasis is a unique disease, endemic in tropical areas, and uncommon in the Western world, making its diagnosis difficult for physicians that are unfamiliar with the disease process. Larvae of a two-winged fly are inoculated through normal skin by a mosquito bite. The larvae grow in the subcutaneous tissues, feed off the surrounding tissues and develop into a fly. A patient with a seemingly commonplace cutaneous lesion which was a harbinger of a much more sinister, unique disease process, is presented. Salient features that characterise these lesions, the difficulty in accurate (and timely) diagnosis, treatment and a review of the literature are discussed with the aim of overcoming limitations of diagnosis and management.

Epidemiological and clinical characteristics of hookworm-related cutaneous larva migrans

Hookworm-related cutaneous larva migrans is caused by the migration of animal hookworm larvae in the human skin. The disease mainly occurs in resource-poor communities in the developing world, but it is also reported sporadically in high-income countries and in tourists who have visited the tropics. Diagnosis is made clinically in the presence of a linear serpiginous track moving forward in the skin, associated with itching and a history of exposure. Itching is typically very intense and can prevent patients from sleeping. Bacterial superinfection occurs as a result of scratching. Treatment is based on oral drugs (albendazole or ivermectin) or the topical application of tiabendazole. To control hookworm-related cutaneous larva migrans at the community level, regular treatment of dogs and cats with anthelmintic drugs is necessary, but this is seldom feasible in resource-poor settings. Animals should be banned from beaches and playgrounds. For protection at the individual level, unprotected skin should not come into contact with possibly contaminated soil.

Cutaneous Myiasis from Panama, South America: Case Report and Review

Background:

Myiasis is a cutaneous infestation with larvae of Diptera, the two-winged arthropod order. Eggs and/or larvae are transmitted directly from the environment or via arthropod vectors. Larvae are able to burrow into the dermis of intact skin or external body orifices. Three clinical variants of myiasis are furuncular, migratory (creeping), and infestation of wounds.

Methods:

A 35-year-old male presented with a 1-month history of worsening furuncles on the left knee and posterior thigh following his return from Panama, South America. Clinical examination revealed tender 6 cm and 2 cm erythematous to violaceous furuncles with surrounding desquamation and central puncta draining serosanguinous fluid. Five-millimeter punch biopsies and tissue swabs were performed.

Results:

All larvae were of the Dermatobia hominis species. The patient was empirically treated with cephalexin and ciprofloxacin for secondary bacterial cellulitis. Tissue swabs later cultured group B streptococcus. A tetanus booster was recommended.

Conclusion:

This case report describes a relatively rare cutaneous infestation with D. hominis, a Central and South American endemic larva of the human botfly. Increasing trends toward immigration and global travel to tropical and subtropic areas will likely increase the frequency of encounters with such parasitic cutaneous infestations in North American outpatient dermatology clinics.

Cutaneous larva migrans in a migrant Latino farmworker

Migrant farmworkers experience a high incidence of skin disease. This report provides information on the case history of cutaneous larva migrans in a Latino migrant farmworker. Treatment options are reviewed, and information for prevention is discussed.

[Cutaneous myiasis over tumor-lesions: presentation of three cases]

We report three cases of myiasis in patients with tumor-lesions. The first patient, a 54-year-old male, presented with laryngeal carcinoma with extensive local involvement, forming a large tumorous mass on the front of the neck that had been irradiated, where several active larvae were seen. The other two patients, females aged 101 and 87 years, respectively, presented with skin tumors on the scalp and face, and several active larvae could be seen in these tumors. After microbiological examination of the larvae removed, the species in the first case was identified as Chrysomya, while the species in the other two cases was Sarcophaga. Several risk factors for developing myiasis have been described, such as advanced age, poor hygiene, diabetes mellitus, venous insufficiency, etc. These manifestations are self-limited, but in most cases treatment is necessary. This consists of cleaning and mechanical removal of visible larvae, with or without occlusion methods.

Oral myiasis: a case report and literature review

Myiasis is the infestation of tissues and organs of animals and humans by certain Dipteran fly larvae. This phenomenon is well documented in the skin, especially among animals and people in tropical and subtropical areas. Oral myiasis is a rare condition and can be caused by several species of Dipteran fly larvae and may be secondary to serious medical conditions. Upon removal of the larvae, the tissues seem to recover with no subsequent complications and with no need for further treatment. Here we describe a case of oral myiasis within the gingiva of a healthy young man caused by the larvae of Wohlfahrtia magnifica (Family Sarcophagidae), in which infection may have been due to ingestion of infested flesh. Reviewing the literature revealed that most cases of oral myiasis tend to be multiple and to occur in anterior segments of the jaws rather than in posterior segments as in the case we describe here.

Uncinaria stenocephala: assessment of antigens for the immunodiagnosis of canine uncinariosis

Although Uncinaria stenocephala is the most frequent hookworm in the intestine of dogs from Northern, Central and Southern Europe, little is known about its host-parasite relationship. Three groups of sera from dogs (Group 1: dogs naturally infected only by U. stenocephala; Group 2: helminth-free dogs at necropsy, and Group 3: dogs parasitized by other helminths) were analyzed by ELISA using U. stenocephala antigens from adult worms (somatic and excretory-secretory antigens) and from L3 larvae (somatic antigens). All three sources of antigens were found to be suitable for immunodiagnosis of canine uncinariosis with up to 90% efficacy. However, an analysis to assess the diagnostic value of the different antigens demonstrated that the adult excretory-secretory antigens had a higher diagnostic efficacy (96.7%), indicating that this is the best antigen source for the diagnosis of Uncinaria infection.

Neurologic aspects of infections in international travelers

BACKGROUND

As international travel for business and pleasure becomes part of contemporary lifestyle, the clinician today is confronted with an increasing number of travelers returning ill with unfamiliar syndromes. The physician will encounter a myriad of patients with exotic infections, emerging infectious diseases, or resurgent Old-World infections.

REVIEW SUMMARY

This review article will discuss salient points of important infectious diseases associated with overseas travel, provide a syndromic approach to the traveler who returns with neurologic manifestations, and list resources for additional diagnostic, therapeutic, and preventive information.

CONCLUSIONS

As many of infections acquired in other countries can directly or indirectly affect the nervous system, the care of the ill traveler often falls into the hands of neurologists. The contemporary neurologist should therefore be knowledgeable of the clinical manifestations, potential complications, and appropriate management of region-specific infections.