Indian Journal of Dental Research

: 2011  |  Volume : 22  |  Issue : 4  |  Page : 615-

Flies blown disease - Oral myiasis

Rahul Srivastava, Parvathi Devi, VB Thimmarasa, S Jayadev 
 Department of Oral Medicine and Radiology, Rama Dental College Hospital and Research Centre, Lakhanpur, Kanpur, Uttar Pradesh, India

Correspondence Address:
Rahul Srivastava
Department of Oral Medicine and Radiology, Rama Dental College Hospital and Research Centre, Lakhanpur, Kanpur, Uttar Pradesh


Myiasis, a term first introduced by Hope (1840), refers to the invasion of tissues and organs of animals and human wounds and certain body cavities by the dipteran larvae which manifests as subcutaneous furunculoid or boillike lesions. Oral myiasis is a rare pathology and a risk to the patient«SQ»s life. Higher incidence is seen in rural areas affecting the tropical and sub-tropical zones of Africa and America. Myiasis affecting the oro-dental complex is rare. Here is a case report of oral myiasis in an 18-year-old male patient who is mentally challenged with anterior open bite, incompetent lips, and periodontal disease. The lesion was treated with turpentine oil, which forced larvae out and irrigated with normal saline solution. Follow-up examination revealed complete remission and healing of the lesion.

How to cite this article:
Srivastava R, Devi P, Thimmarasa V B, Jayadev S. Flies blown disease - Oral myiasis.Indian J Dent Res 2011;22:615-615

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Srivastava R, Devi P, Thimmarasa V B, Jayadev S. Flies blown disease - Oral myiasis. Indian J Dent Res [serial online] 2011 [cited 2021 Dec 7 ];22:615-615
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Full Text

The term myiasis is derived from the Greek word "myi"= fly. It refers to infestation of living tissues of humans and animals by dipterous eggs or larvae. [1] Oral myiasis was first described by Laurence in 1909. Zumpt described myiasis as "the infestation of live human and vertebrate animals with dipterous larvae which at least for a certain period, feed on the host's dead or living tissues, liquid body substances, or ingested food." [2] Myiasis is a worldwide phenomenon, the prevalence of which is related to latitude and the lifecycle of various species of flies. Higher incidence is reported in rural zones especially in tropical and subtropical areas of Africa and America infecting domestic animals especially in humans who are ill and debilitated. [3] Myiasis involving oro-dental complex is an rare entity.

 Case Report

An 18-year-old male patient who was mentally retarded reported to Department of Oral Medicine and Radiology, with chief complaint of discomfort and bleeding gums in upper front teeth region since 2 days. On examination, the patient was moderately built and nourished with waddling gait. Intraorally, a solitary swelling in the left side of the palate was seen extending anteroposteriorly from right central incisor to the left premolar region extending to the midline, measuring approximately 3 × 2.5 cm in size. Overlying mucosa was erythematous and gingival detachment from 21 to 24 with bleeding was seen. Lips were incompetent and class II division I malocclusion with anterior open bite was also noticed. There was generalized edema of gingiva with bleeding on probing and deposits of stains and calculus was present. Swelling was soft and tender on palpation and on exploration three to four larvae were coming out from the exposed area of gingiva along with multiple tunnels and burrows [Figure 1]. Larvae were tapered in shape, creamy white in color, their segments giving appearance of transverse rows with blackish brown tip anteriorly [Figure 2]. It was preserved in 40% formaldehyde and were identified as larvae of Musca domesticus (housefly).{Figure 1}{Figure 2}

Based on history, clinical examination, and identification of larvae, a provisional diagnosis of oral myiasis was given. Under aseptic conditions wound was flushed with normal saline and treated with topical application of turpentine oil. Exploration of the wound revealed multiple burrows and tunnels and approximately 25 larvae were removed with blunt tweezers. Doxycycline 100 mg twice daily on first day, followed by once a day for 7 days, metronidazole 400 mg three times daily for 5 days, and ivermectin 3 mg twice daily for 5 days was given. The patient was advised to maintain proper oral hygiene and rinse the mouth with 0.2% chlorhexidine, three to four times daily and was recalled after 2 days. Every alternative day, the same procedure was repeated and larvae were removed for five consecutive days until no larvae were found in the wound. The palatal wound was then sutured with non-absorbable braided silk thread and half round needle using a simple interrupted suture technique, the sutures were removed after 7 days and complete healing was seen after 1 month of follow up [Figure 3].{Figure 3}


Oral myiasis is a condition in which the soft tissues of the oral cavity are invaded by the parasitic larvae of the flies. First case of oral myiasis was reported by Shira in 1943, and Lim (1974) reviewed the literature on oral myiasis. [4] Myiasis can be caused by several species, out of which three dipteran families are considered as the main cause of myiasis. These families include the following: [5] Calliphoridae [Figure 4], Sarcophagidae [Figure 5], and Oestridae [Figure 6].{Figure 4}{Figure 5}{Figure 6}

Clinically, myiasis can be classified as primary myiasis and secondary myiasis. Primary myiasis is caused by biophagous larvae that feed on living tissue, which are common in cattle (called bicheiras) and are rare in humans. Secondary myiasis is that caused by the necrobiophagous flies which feed on dead tissue, which is more common type and attacks patients with necrotic lesions. [6]

Myiasis can also be classified depending on the condition of the involved tissue into: (1) accidental myiasis (when larvae ingested along with food produce infection), (2) semi-specific myiasis (where the larvae are laid on necrotic tissue in wounds), and (3) obligatory myiasis (when larvae affect undamaged skin). [2]

Based on the anatomic sites myiasis is subdivided into: cutaneous myiasis, myiasis of external orifices (aural, ocular, nasal, oral, vaginal, and anal), and myiasis of internal organs (intestinal and urinary). [2]

Yazdi classified myiasis as dermal and sub dermal myiasis, facial cavity myiasis, wound or traumatic myiasis, gastrointestinal myiasis, vaginal myiasis and generalized myiasis. [5]

Abdo En et al. classified myiasis as obligatory (when larvae develop in living tissue) and facultative (when maggots feed on necrotic tissue). [1]

Reviewing the literature through PubMed from the years 1998 to 2010 revealed 20 cases of oral myiasis, age ranging from 3 to 89 years, out of which 4 cases were reported from India [Table 1]. Infestations were mostly in the tropics or subtropics and M. domesticus was the most prevalent species found in India. [3] It belong to Kingdom: Animalia, Phylum: Arthropoda, Class: Insecta, Order: Diptera, Family: Muscidae, Genus: Musca , Species: M. domestica [7] [Figure 7].{Figure 7}{Table 1}

Myiasis occurs in the areas in which people live close to livestocks, mostly in rural areas and villages. [5] Factors favoring primary oral infection include halitosis, open mouth with poor oral hygiene, facial trauma, suppurative lesions, and neurological deficit. [8] Myiasis can also be seen secondary to medical or anatomical conditions such as cancrum oris, neglected mandibular fracture, cerebral palsy, mouth breathing, anterior open bite, incompetent lips, and patients undergoing mechanical ventilation. [3] In the present case, it is possible that incompetent lips and the habit of mouth breathing had favored egg laying on the gingiva, where infestation had developed and the neurological deficit would have facilitated the infestation. The house fly M. domesticus is a well-known cosmopolitan pest of both farm and home, always found in association with humans. The house fly has a complete metamorphosis with distinct egg, larvae or maggot, pupal, and adult stages. Warm summer conditions are generally optimum for the development of fly, it can complete its life cycle in 7 to 10 days. Under suboptimal conditions, the life cycle may require up to 2 months. [7] The flies lay over 500 eggs at a time directly over the diseased tissue. The eggs hatch in less than 1 week and the life cycle is completed in about 2 weeks. [9] Early instar larvae are 3 to 9 mm long, typical creamy whitish in color cylindrical but tapering toward the head and have 13 segments of which only 12 are apparent because the first 2 are partly fused. [10] The head contains one pair of dark hooks. These larvae release toxins to destroy the host tissue. Proteolytic enzymes released by the surrounding bacteria decompose the tissue and the larvae feed on this rotten tissue. The infected tissue frequently releases a foul smelling discharge. [11] When maggot is fully grown, it can crawl up to 50 feet to a dried cool place near breeding material and transform to pupal stage. Pupae complete their development in 2 to 6 days at 32 to 37 o C. The emerging fly escapes from the pupal case. The house fly is 6 to 7 mm long with the female usually larger than the male having a wide space between the eyes. The head of the adult fly has reddish-eyes and sponging mouth parts. [7] The larvae obtain their nutrition from the surrounding tissues and burrow deeper into the soft tissues by making tunnels. [9]

Mechanical removal of larvae is the traditional treatment for myiasis. Use of systemic ivermectin can give favorable results. Topical antibiotics can be employed as coadjuvants in the treatment. [8] Ivermectin is a semi-synthetic macrolide antibiotic, isolated from Streptomyces avermitilis. In 1993, ivermectin was reported to be safe for human use. It blocks nerve impulses on the ending nerve through the release of gamma amino butyric acid (GABA), linking to the receptors and causing palsy and death. Acetylcholine, which is the main peripheral neurotransmitter in mammalians, is not affected by ivermectin. [6]

Prevention of human myiasis involves control of fly populations and general cleanliness such as reducing decomposition odors and cleaning and covering wounds. Control of flies is important step to prevent the infestation. Good sanitation is the basic step in any fly management program. Killing adult flies may reduce the infestation, but elimination of breeding areas is necessary for good management. Fly traps may be useful, in case of indoors; ultraviolet light traps to kill them with an electrocuting grid are used. One trap should be placed for every 30 feet of the wall inside the building. Recommended placement areas in the case of outdoors include near building entrances, in alleyways, beneath trees, and around animals sleeping areas and manure piles. Residual wall sprays can be applied where the flies congregate. Outdoors, the use of boric acid in the bottom of dumpsters and indoors, the automatic misters, flypaper, electrocuting, and baited traps can be used to control the fly population. [7]


Oral myiasis is uncommon disease in humans and can take many forms including infection of skin, gut, nasal cavities, eyes, and occasionally the oral cavity. As larvae of flies can destroy vital tissues, inducing serious or even life-threatening hemorrhages, so early diagnosis and management of such infection is essential.


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