The value of Doppler ultrasound in diagnosis in 25 cases of furunculoid myiasis

Emerging infectious diseases of the skin: a review of clinical and histologic findings

Emerging infectious diseases are of great importance to public health and clinical practice. This review aims to characterize the clinical and histopathologic features of emerging infectious diseases with cutaneous manifestations in order to increase awareness of these entities among dermatologists, pathologists, and dermatopathologists.

The Human Botfly "Bubbling Sign": Ultrasound Features of Cutaneous Furuncular Myiasis

Dermatobia hominis , the human botfly, is native to South and Central America with cases of infestation seen in travelers to these areas. Myiasis is the cutaneous manifestation of larvae between two periods of molting (instar) and presents as a firm furuncular mass with a central pore that can be easily clinically overlooked. Ultrasound is useful in the diagnostic workup and has specific features and techniques to demonstrate live larva. We present a patient who acquired cutaneous furuncular myiasis caused by D. hominis , the human botfly, during her jungle trek in the Amazon forests in South America. Over 5 weeks, she developed a firm furuncular lesion with a central pore. Ultrasound revealed a hypoechoic mass with a hyperechoic oblong-shaped core that showed a fluid circulation, confirming the presence of a viable larva. Surgery was performed and a second-instar D. hominis larva was confirmed. We discuss the key ultrasound findings and management of cutaneous furuncular myiasis with the aim of raising awareness of this condition, adding to the growing body of literature likely associated with the re-opening of global travel routes.

Point-of-care ultrasound utilized for foreign body in a toe: A case report of botfly larvae

BACKGROUND

Myiasis, as defined by the Centers for Disease Control and Prevention, is infection with fly larvae commonly occurring in tropical and subtropical areas. Whereas the presentation of skin infection with organisms such as Dermatobia hominis (human botfly) is more easily recognized in these regions, identification of myiasis in the United States is difficult due to its rarity. Due to unspecific signs and symptoms, myiasis may initially be mistaken for other conditions, like cellulitis.

CASE REPORT

This case details a patient with pain, swelling, drainage, and erythema of the right second toe. The patient recently returned from Belize and reported an insect bite to the area approximately 1 month prior. She had been seen by health care professionals twice prior to presenting to our Emergency Department (ED) due to increasing pain. At those visits, the patient was prescribed antibiotics, failing to improve her symptoms. In the ED, point-of-care ultrasound (POCUS) of the soft tissue was performed and showed evidence of a foreign body consistent with cutaneous myiasis. Given the patient's history of travel to Belize and known insect bite, it is prudent to have an increased suspicion for cutaneous myiasis. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: To prevent a delay in diagnosis and unnecessary antibiotics, clinicians should have a high level of suspicion for botfly if a patient reports recent travel in an endemic region and pain disproportionate to an insect bite. POCUS contributes to a more efficient recognition of the disease.

Parasites causing cutaneous wounds: Theory and practice from a dermatological point of view

A wide range of parasites can infest open wounds, or cause wounds due to the effects of the infestation. Parasitic infestations can involve the skin and subcutaneous tissues, with various clinical manifestations. In case of cutaneous wounds related to infestations, protozoa, helminths and arthropods are the main groups of parasites involved and emerging new aspects have been recently reported. Treating the wound correctly is fundamental in these patients in order to reduce the development of pathological scars and prevent complications. In particular, a gentle debridement for devitalized/infested tissue removal, the appropriate use of topical antiseptics and dressings such as hydrogel, hydrocolloids and antimicrobial dressings can be useful to control superinfections, moisture balance, inflammation and to promote edge proliferation.

Cutaneous myiasis in skin cancer and malignant wounds: a systematic review

BACKGROUND

Cutaneous myiasis in patients with malignant wounds or skin cancer is a rare and undesirable event with limited epidemiological data. A subregister of reports, lack of education in the population, inadequate empirical treatments, and medical underestimation are components of a public health problem that threatens patients' lives.

METHODS

We conducted a systematic review of the literature of cutaneous myiasis associated with malignant wounds and skin cancer, characterizing sociodemographic variables, risk factors, clinical and histological features, and treatment. Additionally, we present a demonstrative case with the adequate taxonomic evaluation.

DISCUSSION

Cutaneous myiasis is an underestimated and poorly managed infestation, which can generate severe complications in oncological patients. This is the first systematic review in the literature about this clinical scenario, which provides information to the physician and clinical researcher about the epidemiological gaps and what has been published so far.

CONCLUSIONS

Findings from the current review have helped to display the sociodemographic, epidemiological, and clinical behavior of myiasis in skin cancer and malignant wounds. Its contribution to the greater tumor tissue destruction is clear; however, more studies are required. The therapeutic management in these patients is equally clarified.

Multimodality Imaging of Foreign Bodies: New Insights into Old Challenges

Traumatic wounds and lacerations are a common reason for patients to present to emergency departments, with retained foreign bodies (FBs) accounting for 7%-15% of cases, particularly those involving the extremities. These retained materials result in a granulomatous tissue response known as an FB reaction, a pathologic attempt to isolate the FB from the host. The most common FB materials are glass, metal, and wood, but other compositions can also be found, such as plastic and animal-derived materials. Clinical history, physical examination, and wound exploration are essential in investigation of retained material but are not sufficient to exclude an FB, and additional investigation is required. Imaging evaluation is a useful tool to help depict and locate an FB, assess possible complications, and guide removal. Conventional radiography, the first-line method in this scenario, is a widely available low-cost depiction method that has good sensitivity for depicting FBs. If the retained material is not depicted at conventional radiography, US can be performed. US is highly sensitive in depicting both radiolucent and radiopaque FBs in superficial locations. For deeper objects, CT may be necessary. MRI is the best imaging modality to delineate local soft-tissue and osseous complications. Retained FBs can result in early and delayed complications, with infection being the most frequent complication. To avoid preventable morbidities related to FBs, radiologists should be familiar with imaging findings and provide essential information to help the attending physician treat each patient. Online supplemental material is available for this article. ^©RSNA, 2020.

A dermoscopic study of cutaneous myiasis: other findings

BACKGROUND

Myiasis is a cutaneous infestation by the larvae of dipterous flies. It can be furuncular/nodular, papular, or pustular. Diagnosis of cutaneous myiasis depends mainly on clinical examination especially for the nodular form. The latter two forms can present diagnostic difficulties. Dermoscopy has been reported to be helpful. This report illustrates some of the dermoscopic features of this condition.

METHODS

The history, clinical findings, and dermoscopic findings of 15 affected individuals were documented.

RESULTS

Dermoscopy in all patients showed the posterior end of larvae (creamy-white bodies and respiratory spiracles resembling birds' legs with digitated feet). Larval motility and bubbles were noticed in 15 and 10 of patients, respectively. Skin surrounding the larvae showed hypopigmentation in 11 patients and an increase in dilated capillaries in 13.

CONCLUSIONS

Dermoscopy can facilitate the diagnosis of myiasis particularly of the papular and pustular forms.

The Botfly, A Tropical Menace: A Distinctive Myiasis Caused by Dermatobia hominis

Dermatobia hominis, also known as the human botfly, is native to tropical and subtropical Central and South America and seen in travelers from endemic to temperate regions including the United States and Europe. Cutaneous infestation botfly myiasis involves the development of D. hominis larvae in the skin and is common in tropical locations. The distinct appearance of a cutaneous D. hominis infestation facilitates early diagnosis and intervention where cases are common. However, the identification of D. hominis in temperate regions may prove challenging due to its rarity. D. hominis may be misdiagnosed as folliculitis, an epidermal cyst, or an embedded foreign object with secondary impetigo. One should have a heightened suspicion in someone returning from a vacation in an endemic area, such as Belize. Here we describe the presentation, differential diagnosis, and treatment and encourage enhanced preventative measures among tourists when visiting tropical and subtropical regions. Additionally, we propose a novel classification system for assessing the various stages of infestation and suggest that patients reporting travel to Latin America and experiencing pain disproportionate to an insect bite should lead physicians to consider myiasis caused by D. hominis.

Ultrasound Detection of Human Botfly Myiasis of the Scalp: A Case Report

Dermatobia hominis, also known as the human botfly, is an insect native to Central and South America that is known to parasitize both human and animal hosts through cutaneous infestation by its developing larvae. While human botfly myiasis has been commonly diagnosed through dermatologic findings, the presenting lesions and associated symptoms can be non-specific and often misconstrued as other more common cutaneous diagnoses. Here, we present a case of botfly myiasis of the scalp in which ultrasound was utilized to visualize the larvae and confirm the diagnosis prior to larval removal. In this report, we discuss our patient’s presentation, ultrasound imaging, and clinical course/treatment in order to convey how ultrasound imaging, when available, is a valuable tool in establishing the diagnosis of human botfly myiasis.

Update on parasitic dermatoses

These are cutaneous diseases caused by insects, worms, protozoa, or coelenterates which may or may not have a parasitic life. In this review the main ethological agents, clinical aspects, laboratory exams, and treatments of these dermatological diseases will be studied.

Myiasis caused by Dermatobia hominis in Mexico: morphological and molecular identification using the cytochrome oxidase I gene

Myiasis caused by Dermatobia hominis , the human botfly, is frequent in the Americas, however, scarce morphological and molecular information exist regarding this dipteran. We describe three cases in urban areas of Mexico were D. hominis is not endemic. Morphological and genetic identification were performed using the cytochrome oxidase I as a molecular marker. The mitochondrial cytochrome oxidase I gene is useful for inferring the genetic divergence of D. hominis .

Human Botfly: A Case Report and Overview of Differential Diagnosis

Dermatobia hominis, commonly known as the human botfly, is native to Tropical America. As such, cutaneous infestation by its developing larvae, or myiasis, is quite common in this region. The distinct dermatological presentation of D hominis myiasis allows for its early recognition and noninvasive treatment by locals. However, it can prove quite perplexing for those unfamiliar with the lesion's unique appearance. Common erroneous diagnoses include the following: folliculitis, benign dermatocyst, and embedded foreign body with localized infection. We present a patient who acquired D hominis while she was in Belize. In this report, we discuss the presentation, differential diagnosis, diagnostic tests, and therapeutic approaches of human botfly lesion to raise the awareness about human botfly.

Imported and Autochthonous Cases of Myiasis Caused by Dermatobia hominis: Taxonomic Identification Using the Internal Transcribed Spacer Region

Dermatobia hominis is a fly endemic to and widely distributed throughout the Americas; it is found from the southern regions of Mexico to Argentina. However, because of widespread travel, myiasis has become common in countries where neither the disease nor the species that cause this infection are endemic. Central Mexico, for instance, is not a region where myiasis is endemic. We, thus, describe three cases of D. hominis myiasis: two autochthonous cases from the southern part of Mexico and one imported from Costa Rica. In addition, morphological and genetic identification was performed on the maggots extracted from the patients.

External ophthalmomyiasis due to Dermatobia hominis. A case report

CLINICAL CASE

A 46-year-old woman with no relevant medical history, native of Honduras and resident in Spain for one and a half months. The patient went to the Emergency Department due to inflammation of the upper eyelid of the right eye, with an area that simulated an abscess. This was drained (obtaining hardly any purulent content). Treatment was prescribed with oral and topical antibiotics, as well as an anti-inflammatory drug. One week later the patient returned, with improvement of the inflammatory signs, but with discomfort and corneal erosions. After eversion of the upper eyelid, a «worm» type parasite emerged from the tarsus. The extraction was completed with a clamp, and was later identified as Dermatobia hominis (Dh) by examination of a fresh specimen. The subsequent outcome of the patient was favourable.

DISCUSSION

Preseptal cellulitis in patients from tropical and sub-tropical areas can be caused by Dh.

Eyelid inflammation: An uncommon cause in occidental countries

BACKGROUND

Myiasis designates the infestation of live human and vertebrate animals with dipterous (two-winged) larvae (maggots) and is the fourth most common travel-associated skin disease. Furuncle is the most common aspect of cutaneous myiasis.

CASE PRESENTATION

A 24-year-old Caucasian female had been back from Cap-Vert. She described pruritus, slight pain, and the sensation of a foreign body moving in the eyelid. Physical examination showed a single furuncle-like nodule with surrounding erythema and a central pore of the upper eyelid through which a serosanguinous fluid was exuding. A larval end was visible to the naked eye through the aforementioned pore. Treatment consisted of the application of petroleum jelly (Vaseline®) to produce localized hypoxia. A transparent occlusive dressing was set for a duration of 2 h. The larva, Cordylobia antropophaga, spontaneously externalized to breathe and was extracted.

DISCUSSION

There is an increase in travelers returning from tropical countries. Consequently, travel-associated dermatoses are increasing in non-endemic countries. Context of travel and typical clinical presentation strongly suggested to evoke a cutaneous myiasis. The typical furuncular lesion is a papule or nodule with a central punctum that exudes serosanguinous or purulent fluid. Ultrasound can be used to confirm the diagnosis. Treatment consists of three techniques: methods producing localized hypoxia to force emergence of the larvae, application of toxic substances to the eggs and larvae, and mechanical or surgical debridement. Surgery and antibiotics are usually unnecessary. Prevention of furunculous myiasis is based on vector control and individual actions to improve hygiene.

Nasal Myiasis in Hinduism and Contemporary Otorhinolaryngology

Various case reports on nasal myiasis written during the 1990s and 2000s state that nasal myiasis, which is known as peenash among South Asian natives, is a form of divine punishment in Hindu mythology, but do not provide citations from Hindu scriptures that would suggest this interpretation. This paper aims to discuss the phenomenon of peenash in a historical context by examining medical literature written during the nineteenth and early twentieth centuries, to identify Hindu texts contributing to the belief of some Hindus that nasal myiasis is a form of divine punishment, and to provide an overview of contemporary treatment for and management of nasal myiasis.

A Rare Case of Labial Myiasis caused by Dermatobia hominis

The aim of this article is to present a rare case of myiasis caused by Dermatobia hominis. Myiasis is a disease caused by invasion of tissues of animals and humans by larval stages of dipterous (2-winged) flies. There are few reports of oral myiasis in the literature, mostly related to Cochliomyia hominivorax larvae. We present a case of a 53-year-old man with painful swelling of the left lower lip that was confirmed to be myiasis caused by D. hominis. Though more common in tropical and subtropical regions of North and South America, myiasis should be considered in the differential diagnosis of subcutaneous masses among residents or travelers in endemic areas.

Cordylobia rodhaini infestation of the breast: Report of a case mimicking a breast abscess

Introduction

Myiasis, parasitic infestation of the body by fly larvae, caused by the Cordylobia rodhaini is very rare with only fourteen cases published since 1970. We present a rare case of myiasis mimicking a breast abscess.

Presentation of case

A 17-year-old female presented with a nodular ulcerative lesion in her left breast 14 days following a trip to Ghana. She had been initially unsuccessfully treated with the antibiotic flucloxacillin following a misdiagnosis of a breast abscess. Following application of Vaseline to the breast wound, covering the wound for 2 h and gentle manipulation the larvae was removed successfully and the patient made a good recovery.

Discussion

Presenting as an inflammatory papule with central opening oozing serosanguinous fluid myiasis secondary to C. rodhaini can easily be mistaken for a breast abscess, often avoiding detection by unsuspecting surgeons on initial assessment. In turn ineffective antibiotic treatment is often prescribed leading to further disease progression and associated morbidity.

Conclusion

Myiasis secondary to C. rodhaini is a rare but important differential surgeons should consider in women presenting with an inflammatory breast lesion with a recent history of foreign travel to ensure timely diagnosis and treatment. Ultrasound imaging can be useful in confirming diagnosis and avoiding treatment delays.

Myiasis caused by Dermatobia hominis: countries with increased risk for travelers going to neotropic areas

Here, we review the human botfly (Dermatobia hominis), which belongs to a group of Diptera generically known as "myiasis-causing flies," characterized by the ability of their larvae to develop in animal flesh. In addition to its medical and economic importance, there is an academic interest in this botfly because of its peculiar biology, particularly because a phoretic diptera is needed to complete the life cycle. The larvae penetrate the host's skin, causing furuncle-like lesions that are pruritic, painful, and resemble subcutaneous nodules, producing irreversible perforations in the skin. Although D. hominis is distributed from Mexico to Argentina, a review performed by our working group from 1999 to 2015 determined that the countries with the highest infection rates in travelers are Belize, Bolivia, and Brazil. Interestingly, infected men show a higher variation in the distribution of the lesions than in women. Many treatment schemes have been suggested, including the application of highly dense liquids to the lesion to cause anoxia in the D. hominis larvae. We showed, for the first time, a Bayesian inference between D. hominis and other myiasis-causing flies. The flies grouped into two main clusters according to their capacity to produce facultative and obligatory myiasis, and D. hominis was phylogenetically close to Cuterebra spp.

Point-of-Care Ultrasound Assessment of Tropical Infectious Diseases--A Review of Applications and Perspectives

The development of good quality and affordable ultrasound machines has led to the establishment and implementation of numerous point-of-care ultrasound (POCUS) protocols in various medical disciplines. POCUS for major infectious diseases endemic in tropical regions has received less attention, despite its likely even more pronounced benefit for populations with limited access to imaging infrastructure. Focused assessment with sonography for HIV-associated TB (FASH) and echinococcosis (FASE) are the only two POCUS protocols for tropical infectious diseases, which have been formally investigated and which have been implemented in routine patient care today. This review collates the available evidence for FASH and FASE, and discusses sonographic experiences reported for urinary and intestinal schistosomiasis, lymphatic filariasis, viral hemorrhagic fevers, amebic liver abscess, and visceral leishmaniasis. Potential POCUS protocols are suggested and technical as well as training aspects in the context of resource-limited settings are reviewed. Using the focused approach for tropical infectious diseases will make ultrasound diagnosis available to patients who would otherwise have very limited or no access to medical imaging.

First report of furuncular myiasis caused by the larva of botfly, Dermatobia hominis, in a Taiwanese traveler

A case of furuncular myiasis was reported for the first time in a 29-year-old young Taiwanese traveler returning from an ecotourism in Peru. Furuncle-like lesions were observed on the top of his head and he complained of crawling sensations within his scalp. The invasive larva of botfly, Dermatobia hominis, was extruded from the furuncular lesion of the patient. Awareness of cutaneous myiasis for clinicians should be considered for a patient who has a furuncular lesion and has recently returned from a botfly-endemic area.

Botfly larva masquerading as periorbital cellulitis: identification by point-of-care ultrasonography

Myiasis, or the infiltration of the botfly larvae, is a relatively frequent problem encountered by travelers to parts of Latin America. This is a novel case report that documents a Dermatobia hominis infestation of the left facial region with secondary periorbital cellulitis diagnosed by point-of-care ultrasonography.

Concurrent primary and secondary myiasis on basal cell carcinoma

Myiasis is a disease caused by infestation of fly larvae in human and other vertebrate tissues. It is a skin condition common in tropical and subtropical countries and its predisposing factors are: chronic diseases, immunodeficiency, poor hygiene, senility, psychiatric disorders, skin cancers and ulcerated mucosae. We report the case of a healthy patient who after traumatic injury of a preexisting lesion showed a tumor on the dorsal region parasitized by fly larvae. The histopathological examination performed for the diagnosis of skin neoplasm surprisingly revealed the presence of a partially degenerated larva with characteristics of Dermatobia hominis, suggesting an association of primary and secondary myiasis on basal cell carcinoma.

Simple and effective field extraction of human botfly, Dermatobia hominis, using a venom extractor

After a trip to Belize, a 25-year-old man noticed an erythematous papule on his upper right chest that enlarged over a 6-week period and formed a central aperture. The patient reported feeling movement and intermittent lancinating pains under the skin. The history and examination were consistent with cutaneous myiasis, likely secondary to the human botfly, Dermatobia hominis. The objective of reporting this case is to present a simple method of extraction of a botfly larva using a commercial venom extractor. The patient's upper chest was prepared, and an occlusive dressing was placed over the lesion for 30 minutes. The Extractor Pump (Sawyer Products, Safety Harbor, FL) was applied and activated, and the larva was rapidly extracted completely intact with no significant discomfort to the patient. The wound fully healed without complication. D hominis is a common etiology of cutaneous myiasis endemic to Belize. The larva burrows under the skin of mammals where it develops for a period of weeks before erupting and falling to the soil to pupate. The diagnosis and treatment of botfly infestation is pertinent to doctors in the United States as Central and South America are common travel destinations for North Americans. In this case, a commercially available venom extractor was demonstrated to be a safe, noninvasive, and painless method for botfly extraction in the field without use of hospital resources.

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.

[Dermatobia hominis infection in a 3-year-old child]

In the context of increasing travel to the tropics, outpatient services are more frequently confronted with non-domestic diseases in Europe. A 3-year old child presented with a painful tumor of the scalp. After incision of the furuncle-like lesion, we extracted a larva of the botfly Dermatobia hominis. Botflies are mainly encountered in Central and South America; they should be considered if patients demonstrate a furuncle-like lesion and have returned from a holiday in these endemic regions.

Painful, slow developing abscesses. Furuncular miyasis due to double skin infestation by Dermatobia hominis

BACKGROUND

Myiasis is defined as invasion of tissues by Diptera flies. The condition is endemic in the forested areas of Mexico, Central and South America.

MAIN OBSERVATIONS

A 61-year-old woman presented with two boil-like inflammatory and painful lesions on her back. She had been travelling in Central America. Biopsies revealed a myiasis with mature third instar larvae of Dermatobia hominis, a diptera fly endemic in this region. Complete surgical excision and systemic antibiosis led to a delayed but complete healing.

CONCLUSION

We presented a patient with a double infestation by Dermatobia hominis. Dermatologists should be aware of this disease, which has become increasingly common in travellers and is seen now also in unusual regions, other than Central and South America.

Furuncular myiasis from Dermatobia hominus: a case of human botfly infestation

BACKGROUND

Travelers to tropical regions are at risk for a myriad of exotic illnesses. Malaria and dengue are diagnoses that are associated with insect bites, in particular, mosquito bites, acquired while traveling in foreign, tropical countries. Infestation with Dermatobia hominus, the human botfly, endemic to South and Central America, is usually transferred via a mosquito vector. The human botfly should be considered in patients who have traveled to these endemic regions and present with a mosquito bite history and non-healing skin lesions.

OBJECTIVES

We present this case to increase awareness among emergency physicians regarding furuncular myiasis from the human botfly.

CASE REPORT

A 39-year-old pregnant woman presented to the Emergency Department (ED) with an intensely pruritic lesion to the right calf and mild systemic symptoms 6 weeks after travel to Belize. The lesion she thought was a mosquito bite had persisted despite escalating treatment modalities and had been incorrectly diagnosed by multiple physicians.

CONCLUSION

Parasitic disease is not always a systemic process. Botfly infestation presents as local boil-like lesions that are irritating and uncomfortable. Once correctly identified, it can be easily treated in the ED.

[A furoncular ankle cellulitis in a teenager with a difference: Dermatobia hominis]

We report a case of botfly myiasis presenting as an ankle cellulitis in a teenager returning from Guyana. Main clinical features and therapeutic approaches are described.

[Tungiasis and myiasis]

Tungiasis (sand flea disease) and myiasis are ectoparasitoses, in which the infectious agent resides temporarily in the skin (myiasis) or dies and is eventually eliminated (tungiasis). Both diseases are zoonoses. Whereas in myiasis humans are only an accidental host, in tungiasis the prevalence in humans is similar to that of their domestic animals. In travellers returning from the tropics tungiasis and myiasis are not rare, however they are frequently misdiagnosed. The diagnosis of both infestations is made clinically, and laboratory investigations are not helpful. In tungiasis the clinical picture depends on the stage of the disease. A heavy local inflammation and bacterial superinfection are frequent. Therapy consists in the complete elimination of the parasite. The repellent Zanzarin effectively protects against sand fleas.

Myiasis of the upper eyelid

Myiasis rarely occurs in the eyelids. We report a 3-year-old girl with a myiasis of the upper eyelid after a trip to Central America. A 1.5 cm larva of a Dermatobia hominis was excised. Infestation with D. hominis should be suspected when a localized swelling with a central fistula in an eyelid is present in patients who have been to Central and South America.

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 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.

Sonographic detection of subcutaneous fly larvae in human myiasis

Sonographers increasingly face imported diseases such as subcutaneous myiasis. In myiasis, some fly species such as the American Dermatobia hominis and the African Cordylobia anthropophaga use humans as intermediate hosts for the maturation of their larvae. High-resolution gray-scale and color Doppler sonography enabled us to identify D hominis larvae in 2 travelers to Central America by visualizing their typical shape, segmentations, and the continuous fluid transport inside the larval body cavity and spiracles. The small C anthropophaga larva in an individual returning from Namibia was initially not detected. Only when using color Doppler sonography was the larva discerned by its intralarval fluid transport. Sonography enables clinicians to locate viable subcutaneous larvae in suspected cases of myiasis.

Dermatobia hominis (botfly) infestation of the lower extremity: a case report

We present a report of myiasis, which is the infestation of the body by the larva of flies. In this particular case the patient traveled to Belize and was infested in her foot and leg by Dermatobia hominis or the human botfly. Treatment was initiated once she returned to the United States. She ultimately underwent surgical excision of the larva, which was noted to be alive and moving upon removal. This is a rare larval infestation in humans, but is frequently seen in domestic and livestock animals in Central and South America. With increased international travel, the foot and ankle surgeon should be aware of this parasitic infection in recent travelers to Central and South American countries. ACFAS Level of Clinical Evidence: 4.

Botfly myiasis: a case report

Cutaneous infestation by the human botfly, Dermatobia hominis, results in furuncular myiasis. This condition is endemic to the forested areas of Mexico, Central and South America. However, because of widespread travel, furuncular myiasis has become more common in North America. Misdiagnosis and mismanagement can occur owing to limited awareness of the condition outside endemic areas. To our knowledge, there is only a single report of botfly myiasis in the recent emergency medicine literature, which is surprising since the emergency department is likely to be the place many patients with this condition first seek attention. We present and discuss the case of a 50-year-old man with furuncular myiasis acquired in Belize. Parasitic infestation should be included in the differential diagnosis of a new skin lesion in patients who have travelled to endemic areas.

Tungiasis and myiasis

Tungiasis and myiasis are common ectoparasitic infestations that occur in developing countries in the tropics, particularly where poverty and poor standards of basic hygiene exist. The growth in international travel to and from these regions has led to an increase in the presentation of these conditions in nonendemic countries. Despite recent progress in the treatment and prevention of tungiasis and myiasis, diagnosis can present a challenge to those unfamiliar with these conditions, especially when they present in nonendemic countries. Tungiasis is caused by the penetration of the female sand flea, Tunga penetrans, into the epidermis of the host. Myiasis is a parasitic infection of the skin and mucous membranes in which the larvae of Diptera insects penetrate healthy or altered skin depending on the species. Infestations are usually self-limited and present few complications. Social neglect and inadequate health behavior in economically depressed urban neighborhoods, however, may lead to secondary infections and complications.

Case report: cutaneous myiasis caused by Dermatobia hominis, the human botfly

Cutaneous myiasis caused by Dermatobia hominis, the human botfly, involves the infestation of human tissue with fly larvae, and is common in Central and South America. We report a case of a 57-year-old man with cutaneous myiasis imported into the US from Belize. The epidemiology, biological life cycle, clinical presentation, and various methods of larval extraction, including incision and drainage, are discussed.

Ectoparasitic infestations

Ectoparasitic infestations are highly prevalent in resource-poor populations throughout the world and are associated with considerable morbidity. Reliable data on the epidemiology, immunology, and therapy of ectoparasitic infestations and on the biology of the parasites remain scarce. The control of parasitic skin diseases, such as scabies, pediculosis, tungiasis, myiasis, and cutaneous larva migrans in endemic areas remains a challenge. Using appropriate study designs, it is imperative to increase further the knowledge on the various aspects of the parasites and the infestations they cause.