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

• Myiasis of the Throat

What is Throat 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
• Throat Myiasis is a rare form of myiasis that develops in the throat due to infestation by fly larvae or eggs, usually from handling farm animals, such as sheep and goats, mostly in the endemic regions. The main causative agent for the condition is the sheep bot fly (Oestrus ovis)
• Throat Myiasis may present throat irritation, coughing, burning sensation, and other symptoms that resemble an allergic condition. It 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, if necessary. The prognosis of Throat Myiasis depends on its severity, but is mostly good with appropriate and speedy treatment

Who gets Throat Myiasis? (Age and Sex Distribution)

• Throat Myiasis may be observed in individuals of any age group, including children and adults
• Both males and females are affected; but, many cases are reported among males
• Worldwide, individuals of all racial and ethnic groups may be affected. However, many cases are reported from the endemic regions of Italy and Iran
• Most of the cases are recorded between the months of April and September

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

There are a variety of risk factor for Throat Myiasis (mainly in the endemic regions). Often, a combination of risk factors may be observed. The predisposing factors include:

• Frequent contact with sheep and goats: Throat Myiasis is considered an occupational hazard in the endemic regions; individuals handling these domestic animals, may have a high risk for infection
• Poor personal hygiene
• Living in poverty and overcrowded unclean surroundings, low socioeconomic status
• Alcoholism and drug addiction
• Immunocompromised status
• Bedridden patients who cannot care for themselves

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 Throat Myiasis? (Etiology)

• Throat Myiasis is a parasitic infection of the throat that is predominantly caused by the sheep bot fly (Oestrus ovis), particularly from exposure to sheep and goats
• Rarely, the maggot may move (or drop) from the nasal cavity (nasal myiasis) to infect the throat

What are the Signs and Symptoms of Throat Myiasis?

The signs and symptoms of Throat Myiasis may vary from one individual to another and may also depend on the type of causative larva species. A sudden onset of the signs and symptoms are observed, which include:

• Foreign body sensation due to movement of larva in the throat
• Itching and burning sensation in throat
• Mild to severe coughing due to throat irritation
• The symptoms may initially resemble an allergic condition that include wheezing, sneezing, constant runny nose, tearing from the eyes, and irritation of the ear, nose, and throat
• Pain in the region
• Pharyngeal inflammation (due to pharyngeal myiasis)
• Difficulty in speaking, hoarse voice
• Difficulty in breathing
• Bad breath

How is Throat Myiasis Diagnosed?

Throat 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
• Oral and ENT examination
• Imaging studies of the head and neck region
• 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 Throat Myiasis?

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

• Severe emotional stress
• Severe pain and discomfort
• Formation of fistula
• Secondary infection of the sinonasal cavities and pharynx
• Infestation of the respiratory tract
• Cellulitis: Skin infection that involves the deeper skin tissues
• Hypereosinophilia and leukocytosis (increased white blood cells)
• Severe inflammatory response to dead larvae or parts of larvae, especially during its removal
• Sepsis, which can be life-threatening

How is Throat Myiasis Treated?

The treatment of Throat Myiasis may involve:

• Swallowing warm oil may force larvae out of the throat mucosa for easy removal
• Throat may be sprayed with lidocaine to immobilize larvae and prevent them from latching onto the mucosal surfaces
• The individuals may be asked to gargle saline solution and spit out the contents
• Surgical extraction of the maggots may be undertaken if necessary, followed by surgical debridement of necrotic tissue
• Administration of broad-spectrum antibiotics

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

How can Throat Myiasis be Prevented?

Throat Myiasis may be prevented by considering the following measures:

• Maintaining good personal and body hygiene
• Handwashing with soap and water before handling food/meat or eating
• Maintain basic personal and community hygiene and proper sanitation is highly important, particularly in the endemic zones
• Wearing gloves while handling sick or dead animals
• Taking steps to rear healthy farm animals, such as by vaccinating the herd and cleaning sheds regularly
• Quarantining infected herds and eliminating them from the healthy stock of animals
• Undertake prompt treatment of any nasal ulcers/wounds and medical conditions related to the nose and throat
• Stop drug abuse and limit alcohol intake
• The growth of adult flies must be effectively controlled and methods for eradication followed on a regular basis

Individuals with compromised immunity are strongly recommended to avoid handling farm animals or hold similar occupations.

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

The prognosis of Throat Myiasis may vary from one individual to another depending on its severity. However, in many cases, the prognosis is good with early diagnosis and treatment (removal of all larvae).

• Extensive tissue destruction with involvement of the respiratory system and delayed/inadequate treatment may result in severe complications
• In some individuals, rupture of an abscess containing the larva may lead to a severe inflammatory response

Additional and Relevant Useful Information for Throat Myiasis:

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

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