Hypereosinophilia due to myiasis

Are Cutaneous Reactions to Fly Larvae Mediated by CD4+, TIA+ NK1.1 T Cells?

Background:

Although there have been reports of fly larvae in wounds and as isolated primary infestations, there have been only rare reports documenting reactions to the larvae within the skin in humans and animals. There have been no reports documenting the histopathologic and immunohistochemical characteristics of the inflammatory infiltrate.

Objective:

We present a patient who developed local pruritus, erythema, and swelling approximately three weeks after infestation by a fly larva within the scalp. Histopathologically the biopsy site showed a mixed infiltrate containing lymphoid cells and numerous eosinophils. Immunohistochemical stains showed predominantly CD4+ T cells expressing an αβ T-cell receptor (TCR) of which approximately 30% coexpressed T-cell intracellular antigen (TIA) and CD56. In addition, there were approximately 5% of these CD4+ T cells which coexpressed CD30.

Conclusions:

Histopathologic and immunohistochemical findings are consistent with an effector cell population of cytotoxic CD4+ T cells that produce a T-helper 2 cytokine pattern. The phenotype of this subset of T cells is unique and among its characteristics is that antigens—usually nonprotein antigens—are presented to these CD4+, TIA+ natural killer (NK)1.1T cells by CD1d molecules.

Myiasis (fly disease) and insectal disease generally are causing mental illness

Mental illness by which psychosis is meant here is known to be caused mainly by imbalances of certain neurotransmitters in the brain. But, what is causing these imbalances? There has been a recent flurry of interest focusing on the possibility of parasitical disease. The appropriateness of this is based on the fact that organisms of the animal kingdom produce the same neurotransmitters. In fact stinging insects release them in their venoms. The proposal here is that insect larval parasites acting on the human brain and body may release such neurotransmitters and cause imbalances and altered mental states and is supported by the occurrence of previously unexplained physical symptoms such as; diarrhoea, constipation, spasms, anaemia, bloating, insomnia, headache, migraine, weight loss, low blood pressure, low grade fever, amnesia and signs of allergy which may accompany mental illness. Some of these symptoms have been previously attributed to the medications prescribed to alleviate the psychotic symptoms but, many are also parasitical signs. It is proposed that the minute larvae may make sudden movements and may be highly motile and may move from pressure, hence evading the phlebotomist's needle. There is also the testimony of those with delusional parasitosis and related addictions, I propose the regularity with which humans are bitten, stung and have their foods infected with insects at all stages as a demonstration of how insectal disease may have the potential for common infection and disease; mental and physical.

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.

First diagnosis of an imported human myiasis caused by Hypoderma sinense (Diptera: Oestridae), detected in a European traveler returning from India

This paper reports a case of myiasis caused by Hypoderma sinense in a European man returning from a journey through northern India. The patient showed eosinophilia, systemic signs of inflammation, and painful swellings in several parts of the body. The diagnosis was confirmed by specific serology and parasite molecular identification.

Cutaneous myiasis caused by Hypoderma lineatum

Cutaneous myiasis is a temporary parasitic infestation of the skin of domestic and wild animals and occasionally of humans by the larvae of flies. Larvae of many flies from various geographic areas can cause myiasis: in Central and South America, human cutaneous myiasis is mainly caused by the larvae of Dermatobia hominis; in Africa, by the larvae of Cordylobia anthropophaga; in the northern hemisphere (North America, Europe, Africa and Asia), by the larvae of Hypoderma spp. A case of cutaneous myiasis in a 47-year-old woman, co-author of the present report, is described. She returned to Slovenia from a three-week trip to Ladakh in Northern India. The parasite, nested in tumor-like swelling about 1-2 cm in diameter and 0.5 cm high in her neck, was removed. The parasite was identified by its morphological characteristics as the larva of Hypoderma lineatum. After the removal of the larva, which was yellowish-white, oval-shaped and about 6 mm long and 1.5 mm wide, the lesion healed in two weeks without further treatment. Clinical and laboratory staff will need to be alert in the future, not only to myiasis caused by Dermatobia and Cordylobia larvae from tropical and subtropical areas but also to Hypoderma larvae from the Himalayan area from where the patient returned to Slovenia.

Unusual MRI findings in a patient with history of frontal fracture and skin infestation by fly larvae, as a possible sign of intracerebral myiasis

We report a case of an 11-year-old columbian immigrant with mild non-specific cephalalgia. He had a previous history of frontal fracture and skin infestation caused by Dermatobia hominis larvae. MRI performed revealed multiple subependymal and intraventricular lesions with concentric blooming artifacts and moderate hydrocephalus. Based on his previous history, intracerebral myiasis diagnosis was suggested. His mother denied any kind of diagnostic surgery or treatment. To the best of our knowledge, this is the first MRI report of a possible intracerebral myiasis, an exceedingly rare entity.

A case of furuncular myiasis associated with systemic inflammation

Cutaneous myiasis is a common travel-associated dermatosis caused by fly larvae. We report an unusual case of furuncular myiasis caused by Dermatobia hominis that was associated with signs of systemic inflammation. In this case study, morphological and novel molecular approaches were used to identify and characterize the larvae responsible for human infestation.

Furuncular myiasis caused by Dermatobia hominis, the human botfly

Myiasis is a common travel-associated dermatosis. Travelers to many parts of Central and South America are susceptible to infestation by Dermatobia hominis. Despite the common name of human botfly, D hominis infests a broad range of mammals and is a severe pest to economically important farm animals in endemic regions. The adult female does not lay the eggs on the host. Instead, the adult female infests hosts indirectly by using blood-feeding arthropods to serve as phoretic vectors to transport the eggs. We present a patient who acquired Dermatobia when bitten by a day-active mosquito during a visit to Guatemala. He had a locally painful, firm furuncular lesion with a central pore that drained serosanguineous exudates. The patient applied an occlusive ointment and recovered the larva after it emerged. In this report we discuss the life cycle of D hominis, the differential diagnosis, and therapeutic approaches.

[Subcutaneous myiasis. A case report]

Although myiasis or hypodermiasis is a parasitic disease that theoretically has practically been eradicated, a new case has recently been reported in Lower Normandy, in a bovine husbandry region.

CASE REPORT

A seven-year-old-girl was hospitalized in November 1998 for an edema of variable size on the right eyelid, which was not painful and non-inflammatory, with accompanying ptosis. A number of subcutaneous nodules were found on the forehead above the right eye socket. The right eye itself was unaffected. The symptoms had evolved over a ten-day period. Further examination did not detect any sign of eosinophilia, and the hypodermiasis and toxocariasis serologies were negative. The clinical evolution was characterized by the regression and reappearance of the edema on several occasions, after which the edematous mass became progressively larger, more swollen and painful, so that it was no longer possible to open the eye. The subcutaneous nodules partially disappeared when the edema increased in size. Six weeks after the onset of clinical signs, eosinophilia was observed and the hypodermiasis serology was positive. Due to the limitation of the visual field as a result of the edema, a short-term steroid treatment (seven days) was orally administered. The patient recovered, and no further edematous signs were noted. However, contrary to what had been reported in the literature, the larvae did not appear on the surface of the skin.

CONCLUSION

In conclusion, in bovine husbandry regions the diagnosis of hypodermiasis should always be kept in mind in the event of clinical signs indicative of larval migration, even in the initial absence of eosinophilia, and even with an initially negative hypodermiasis serology. This disease should soon be eradicated, as regional bovine treatment programs have been set up to systematically treat the cattle and eliminate the larvae.

Myiasis due to Hypoderma lineatum infection mimicking the hypereosinophilic syndrome

Myiasis is the infestation of live humans with larvae of Diptera (true flies). This report describes a protracted illness caused by infestation with Hypoderma lineatum, resembling the hypereosinophilic syndrome. A 35-year-old man had a 9-month multisystemic illness with pronounced eosinophilia, pleuritis, pericarditis, and myositis. Treatments including glucocorticoids did not alter the disease. Diagnostic studies included computed tomography, 2-dimensional echocardiography, leukocyte count, surgical biopsy of skin and muscle, blood immunoglobulin levels, and blood chemistry. Myiasis was recognized when a worm emerged from the patient's skin; after a second worm emerged, the patient's symptoms disappeared rapidly. Other determinations included IgE and IgG levels specific for H lineatum, Western blot, and immunofluorescence for eosinophil major basic protein; IgG antibodies to H lineatum decreased after emergence of the worms. The patient's symptoms mimicked the hypereosinophilic syndrome but resolved when the myiasis became apparent. Specific serologic analyses can identify infected patients, and ivermectin may be useful as treatment.

Hypereosinophilia

Recent advances in our understanding of hypereosinophilia have related particularly to the definition of criteria for distinguishing between eosinophilic leukemia and the 'idiopathic' hypereosinophilic syndromes. In this article, leukemogenic mechanisms have been identified in a number of subtypes of eosinophilic leukemia, and the role of clones of T lymphocytes in the causation of otherwise unexplained eosinophilia has been further elucidated. The roles of various therapeutic modalities-including cytotoxic chemotherapy, interferon and bone marrow transplantation-in eosinophilic leukemia and in the idiopathic hypereosinophilic syndrome also have been further defined.