What are the other Names for this Condition? (Also known as/Synonyms)

• Myiasis of the Ear
• Otomyiasis

What is Aural Myiasis? (Definition/Background Information)

• Myiasis is primarily a skin disease caused by several species of parasitic fly larva (of taxonomic order Diptera). The fly larvae (maggots) cause disease in humans and other vertebrate animals by feeding on the tissues. The infection is usually characterized by a painful, itchy, boil-like skin lesion that contains the parasite within it
• Aural Myiasis or Otomyiasis is an uncommon form of myiasis that typically develops in the external and/or middle ear presenting earache, mild to severe hearing impairment, itching, and pus-filled to bloody discharge
• The factors that may cause Aural Myiasis include poor standards of living, severe otitis media (ear infection), mental retardation, and poor personal hygiene, among other factors. The condition is usually caused by screw-worms and flesh flies that lay their eggs or deposit larvae in the ear canal
• Aural Myiasis can cause severe and extensive tissue destruction and serious complications, if not immediately addressed. Management of the condition involves removal of all larvae followed by surgical debridement of necrotic tissue. Nevertheless, the prognosis of Aural Myiasis depends on its severity; mild cases have better prognosis than severe cases

Who gets Aural Myiasis? (Age and Sex Distribution)

• Aural Myiasis may be observed in individuals of any age group; many cases are noted in young children and elderly adults, who cannot take care of themselves
• Both males and females are affected, and no gender preference is noted
• Worldwide, individuals of all racial and ethnic groups may be affected. However, most of the cases are reported in developing countries of Asia, Africa, and South America, in the tropical regions

What are the Risk Factors for Aural Myiasis? (Predisposing Factors)

There are a variety of risk factors for Aural Myiasis (mainly in the endemic regions). Often, a combination of risk factors may be observed.

• Living in poverty and overcrowded unclean surroundings, low socioeconomic status
• Poor personal hygiene
• Chronic suppurative otitis media (severe ear infection)
• Old age
• Children of neglect, particularly those below age 10
• Differently-abled people, especially those with mental disabilities
• Psychiatric illnesses: Elderly adults, especially those with certain neurodegenerative conditions
• Bedridden patients who cannot care for themselves
• Swimming in dirty and stagnant waterbodies
• Longstanding ear drainage (otorrhea) is a risk factor in healthy individuals
• Uncontrolled diabetes
• Immunocompromised status
• Alcoholism and drug addiction

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Aural Myiasis? (Etiology)

Aural Myiasis is a parasitic infection of the ear caused by any of the following species of insect larvae (maggots):

• Flesh flies (Sarcophaga sp.)
• New World screw-worm fly (Cochliomyia hominivorax)
• Old World screw-worm fly (Chrysomya bezziana)
• Oriental latrine fly (Chrysomya megacephala)
• Spotted flesh fly or screwworm fly (Wohlfahrtia magnifica)

The parasitic insects either lay eggs or deposit their larvae in the aural cavity; up to 200 eggs may be laid by an adult fly. The condition may develop in children and older adults due to factors such as poor hygiene, chronic ear infections, and weakened immunity.

What are the Signs and Symptoms of Aural Myiasis?

The signs and symptoms of Aural Myiasis may vary from one individual to another and may also depend on the type of causative larva species. In many individuals, the following may be noted:

• Individuals may sense a presence of foreign body in the ear. Movement sensation of the maggots in the ear may be noted
• Ear pain (otalgia)
• External ear may be red and swollen
• Drainage of blood and/or pus from the ear
• Foul smell from the ear
• Ringing in the ear (tinnitus)
• Vertigo
• Discomfort and restlessness
• Hearing loss that may be mild or severe, typically in one ear
• Bilateral involvement (both ears being affected simultaneously) is extremely rare

Additionally, systemic signs and symptoms, such as fever and chills, may be noted.

How is Aural Myiasis Diagnosed?

Aural Myiasis is diagnosed on the basis of the following information. The diagnostic techniques used may vary based on the specific type of causative parasite.

• Complete physical examination and a thorough medical history evaluation
• Hearing and audiometric tests
• Otoscopy: Examination using an instrument that allows the physician to look inside the ear; a visualization of the ear may reveal the maggots
• X-rays, MRI scan, or CT scan of the head and neck region
• Neurological, motor skills, and cognitive assessment, if necessary
• Laboratory tests: Blood tests, such as complete blood count and peripheral blood smear

A differential diagnosis to eliminate other conditions/infections may be considered, before arriving at a definitive diagnosis.

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Aural Myiasis?

The complications of Aural Myiasis can be significant and may include:

• Severe emotional stress
• Severe pain and discomfort
• Secondary infection of the abscess; rupture of the abscess
• Hypereosinophilia and leukocytosis (increased white blood cells)
• Eardrum perforation
• Facial weakness if the cranial nerves are affected
• Complete hearing loss, typically unilateral
• Migration of larvae into the nasal cavity
• Severe cases may present neurological symptoms, such as seizures, due to meningitis
• Severe inflammatory response to dead larvae or parts of larvae, especially during its removal
• Sepsis, which can be life-threatening

Penetration of maggots into the brain may result in significant and life-threatening complications that can result in fatalities.

How is Aural Myiasis Treated?

The treatment for Aural Myiasis may involve the following measures:

• Immobilization of the larvae using ethanol, chloroform, oil, or other agents
• Irrigation of the ear canal using saline solution, both before and after removal of larvae
• Manually removing larvae/maggots after visualizing them microscopically; suctioning may be used by some healthcare providers to help remove the parasitic larvae
• Surgical measures may be needed for deeper infestations, such as when the middle ear is involved
• Oral medications containing ivermectin
• Administration of broad-spectrum antibiotics, as needed

Examination and identification of the larva following removal from skin tissues may be undertaken.

How can Aural Myiasis be Prevented?

Aural Myiasis may be prevented by considering the following measures:

• Maintain good oral hygiene
• Avoid substance abuse and limit alcohol intake
• Controlling diabetes through lifestyle changes
• Undertake prompt treatment of any ear infections or aural medical conditions
• Maintain basic personal and community hygiene and proper sanitation is highly important, particularly in the endemic zones
• Avoid playing or swimming in stagnant water
• Use insect repellents to prevent the insects from entering residences
• The growth of adult flies must be effectively controlled and methods for eradication followed on a regular basis

What is the Prognosis of Aural Myiasis? (Outcomes/Resolutions)

The prognosis of Aural Myiasis may vary from one individual to another depending on its severity.

• Aural Myiasis, where involvement of the external and/or middle ear is noted, with prompt treatment and removal of all maggots can result in good prognosis
• When the internal ear is involved and/or the parasitic larvae invades into brain tissue, the outcomes may be guarded
• Extensive tissue destruction and delayed/inadequate treatment may result in severe complications that may even be fatal
• In some individuals, rupture of an abscess containing the larva may lead to a severe inflammatory response

Additional and Relevant Useful Information for Aural Myiasis:

The following DoveMed website link is a useful resource for additional information:

https://www.dovemed.com/healthy-living/skin-disorders/