Auricular Myiasis in Children: Case report of Unexpected Foreign Bodie

The term myiasis is derived from the Greek word “myia” meaning fly, was first created by Hope (1840). This term referred to the only clinical manifestations caused in humans by dipterous larvae (maggots), as opposed to those caused by insect larvae in general. [1] Subsequently, the meaning of the word has been extended to animal infestations which are also the more frequent because these larvae are essentially animals parasites and occasionally provoke human myiasis.

Auricular myiasis presents a rare and a unique clinical entity, it is rare in adults but frequent on among children; only a small number of case series have been reported [2]. Humans represent only a target of opportunity; it is frequent in rural and slum areas where unhygienic conditions are prevalent. Therefore, there is a Lack of available evidence to guide management of this disease [3]. We report a rare case of auricular myiasis on a child with immune deficiency history.

A 2 years and 6 months old girl presented with a 2 years’ history of chronic right ear otorrhea. The mother reports the notion of fever and otorrhea 6 months after birth, for which the girl has been hospitalized for 3 months in the infectious disease department, where the diagnosis of immune deficiency was evoked. (Blood Cell Count (CBC), Measurement of Oxidative Burst in Neutrophils, Expression of HLA-DR antigens, and immunologic tests were normal) different courses of oral and local antibiotics had been previously prescribed but were ineffective.

The girl has been referred to our ENT department for a complementary care management. The girl was admitted with the complaint of chronic otorrhea, otalgia and itching in the external auditory canal. The mother reported the extraction of maggots from the external auditory canal. CT scan showed a filling of the external auditory canal, middle ear and the mastoid cells without any bone lysis (Figure 1).

Figure 1: CT scan showing filling of the external auditory canal, middle ear and the mastoid cells

Upon examination with a general anesthesia, maggots showed at the middle ear after the aspiration of the draining right ear, with a large perforation. The maggots were extracted with clamp (Figure 2).

Figure 2: Maggot at the external auditory canal (A), and after extraction (B).

Saline irrigation and concomitant suction were performed. Combination antibiotic/steroid preparations were given pre- and post-micro toilet evacuation of the maggots, 3mg of ivermectine was administrated after extraction in one dose.

Maggot have been addressed in physiological saline at the parasitology laboratory and mycology, the myiasis was confirmed but fly species was not determined due to poor transport conditions, and the manipulated maggot. After 3 weeks follow up, the girl remained free of symptoms, and endoscopic examination showed the beginning of perforation closing (Figure 3).

 

Figure 3: Clean extern auditory canal, with beginning of closing perforation.

Myiasis is a type of parasites is which involves the infestation of living vertebrate animals with fly larvae which feed on host’s necrotic or living tissue, liquid body substances or ingested food. Depending on the affected organ, myiasis can be classified in nasopharyngeal, oral, cutaneous, urogenital and, as in our case aural myiasis [3]. Aural myiasis has been defined as infestation of middle and/or the external ear, involvement of the pre-auricular region should also be included. A recent review article, considers that sanitary conditions, low socioeconomic status play an important role in general, however specifically aural myiasis has been previously suggested to be more common in children, in patients with chronic otorrhea, patients swimming in stagnant waters and/or in debilitated individuals [2,4].

Neglected chronic suppurative otorrhea was the most suspicious cause in our case. The clinical presentation is wide from maggots in the ear to otalgia, ear drainage, Perforation of drum, itching roaring sound, tinnitus, bleeding. Otalgia is the most common pathological symptom of aural myiasis, otorrhea may be the second frequent symptom. Severe infestation may lead to deafness and meningitis. The surrounding tissue of the ear canal including bones may be damaged by the larval attack [3,5]. The examination of auditory function before and after treatment will be necessary if the patient repot hearing loss.

In our case the symptoms were the otorrhea and maggots in the ear; auditory function was not examined by audiogram. Taxonomic division establishes several families derived from the order Diptera: Oestridae, Calliphoridae and Sarcophagidae are the most important. The species Wohlfahrtia magnifica, which belongs to the latter family, is a must-type larva, meaning that it requires living in a host tissue to complete its development. This species is the predominant etiologic agent worldwide [4,6].

In our population (morocco) sarcophagidae is the most frequent family [7], in our case fly species was not determined due to poor transport conditions. Singh and Rana (1989) reported that the identification of the species of maggot prior to the recommendation of treatment is important because not all types of myiasis are benign [5]; however in our case despite the lack of identification the outcomes were satisfactory.

After having diagnosed myiasis through physical examination and, in some cases, through diagnostic images, the treatment must begin as soon as possible, including removal of maggots and cleaning lesion with 70% ethanol, 10% chloroform, oil drops, iodine saline or normal saline. Prophylactic antibiotic therapy may prevent secondary infections. The treatment is simple in early stage [4,5].

According to literature, maggot’ sex traction, normal saline irrigation with concomitant suction and antibiotics were performed in our case. The ultimate goal of any treatment regimen is complete maggot removal and the easiest approach would likely be microscopic removal of all maggots with subsequent use of otic antibiotic drops [8]. Different studies have reported the occurrence of aural myiasis in humans [3], hence the interest of watchful waiting.