in Colombia as the climate favors different species of flies. In general, all
share the same pathophysiological mechanism that begins when the female
deposits eggs in the biological tissue to allow the development of the larvae,
developing the infection and depending on the anatomical site compromised,
possible complications can occur, we report a unussual severe aural myiasis.
presentation: A 71-year-old male with insulin-dependent type 2
diabetes mellitus, with a 4-day evolution of a lesion in the pinna. Consulted
to our emergency room, presentinglarvae in helix.Physical
examination showed necrosis of 80% of the helix with abundant myiasis inside,
helix and antihelix cartilage exposure in the anterior and posterior portions,
with necrotic tissue, fetid, edema and erythema of the entire pinna with no
impact on the preauricular region, computed tomography showed no damage of the
mastoid.The subsequent analysis identified larvae of Cochliomyia hominivorax.
and Outcome: Thetreatmentconsisted in larvae extraction,
ampicillin/sulbactam and clotrimazole drops, after a 16-day hospitalisation,
the patient was discharged without complications. Later the pinna was
reconstructed using skin flaps.
superficial wound attracts a dipterous female that deposits its eggs, allowing
for the development of early larvae that feed on healthy tissue. Pain and edema
prompt the patient to seek medical attention where the diagnosis is simple
through the visualisation of larvae in the tissue and larvae extraction.
Antibiotics and ivermectin are used for treatment of the infection and in this
case, surgical debridement was performed. As in other cases, staphylococcal
superinfection is reported.
Aural Myiasis; Diabetes Mellitus; Larvae; Necrosis; Pinna; Staphylococcus; Superinfection
tropical countries, due to their climatic characteristics and environmental
variables, the population is exposed to a greater number of infectious
diseases, such as parasitic infestation which can affect the intestinal,
muscular, pulmonary and neurological systems; according to the etiology the
dipteral infections are less frequent entities.
types of flies can deposit their eggs, the combination of the interactions
between the climate, socioeconomic conditions and the medical history of the
host will allow the development of Myiasis [1-2].In
this case report a Colombian patient developed a severe aural Myiasis which
required a reconstructive surgery for loss of aural tissue. A brief discussion
and update of these infections is presented from the emergency department.
2. Case Presentation
71-year-old male who works in agriculture and has a history of
insulin-dependent type 2 diabetes mellitus, but is poorly adherent and has had
previous vascular complications, was treated as a patient in our Emergency
Department. His clinical picture is that of a 4-day-old injury that he suffered
whilst performing an agricultural chore. The patient reported that he
accidentally cut his right pinna causing a shallow laceration and that 24 hours
later it was surrounded by flies so he decided to put homemade ointments on the
wound. Later he noted edema in the pinna, local pain and larvae in the helix
and so decided to come to the Clinic.A physical examination showed necrosis of
80% of the helix with abundant myiasis inside (Figure 1
and Figure2), helix and antihelix cartilage exposure in the anterior and
posterior portions, with necrotic tissue, fetid, edema and erythema of the
entire pinna with no impact on the preauricular region nor the mastoid. There
were no changes to the auditory canal, nor was otorrhea present. The tympanic
membrane was intact and healthy and a cone of light was present.
approximately 100 larvae were extracted, initially flushing with saline
solution using pressure and with sterile forceps. Multiple cavitations,
destruction of skin and cartilage, and septa and multiple subdermal pockets
occupied by larvae are all evident. The tomography (Figure
3) shows that only soft tissue was affected.
analysis identified Cochliomyia hominivoraxlarvae. Surgical
debridement of non-viable tissue and lavage was performed, tissue culture was
obtained, necrosis of 90% of the pinna (Figure 4)
was noted and the wound was then covered with gentamicin ointment.
second surgical procedure, the upper, middle and lower third of the helix and
antihelix was amputated.A culture of the sample was performed which identified Methicillin-Sensitive
so the antibiotic was changed to ampicillin/sulbactam and clotrimazole drops
were given for the management of fungal otitis.
16-day hospitalisation, the patient was discharged without complications. Later
the pinna was reconstructed using skin flaps.
by dipteran larvae or myiasis is a common infection in tropical countries as
the climate favours different species of flies. In general, all share the same
pathophysiological mechanism that begins when the female deposits eggs in
biological tissue to allow the development of the larvae. The attraction of the
fly to the tissue depends on specific variables of each species[1-2]. In the case of Cochliomyia hominivorax, the female
is attracted by odors from wounds or cavities that lead her to depositing
between 200 and 300 eggs in the tissue. C. hominivorax larvae do not feed on necrotic
tissue, they hatch in 12 to 14 hours, emitting odors that stimulate more
females to deposit more eggs allowing a cycle of infestation in mammals. For C. hominivorax, the most common risk factors
associated with its infestation are poor hygiene, especially of wounds (even if
they are superficial), natural disasters and low socioeconomic strata. Wounds
in patients with diabetes, cancer, tracheostomies and suppurative lesions are also
associated with myiasis [1-6].Worldwide,
cutaneous myiasis and myiasis wounds are the most frequently seen clinical
cases. Virtually any body region that presents a wound can be infested[2,7]. Aural myiasis or that involving the inner/outer
ear is not so frequent within the anatomical regions affected6, however, this
infestation has been described in all ages in all groups and in different
countries[2,8-10], without the associated
mortality being reported. Even in patients where tympanic membrane and mastoid
is affected2, in this type of myiasis, the main parasite reported is Wohlfahrtiamagnifica,
which has a different biological cycle to C. hominivoraxespecially
in the hatching of the larva: C. hominivoraxis faster, allowing the infection to
develop in a shorter period of time.
other myiasis, the treatment consists basically in the mechanical removal of
larvae which can be done initially with pressurized liquids such as saline,
povidone-iodine and hydrogen peroxide[12,13]. It
is very important to ensure that the larvae are destroyed to prevent
polymicrobial infections. Post-larvae removal treatment is not standardised;
the wound can be covered with topical antibiotics or ointments. In most cases,
oral ivermectin in doses of 150-300 μg/kg is
used for the intent of larval paralysis and death, however tissue culture
continues to be fundamental as bacterial superinfection, especially by Staphylococcus,
is common. Surgical indications in the aural infestation are made in view of
the need to explore the mastoid antrum or mastoid due to the presence of
suspected larvae migrating through a perforated tympanic membrane[14,15] Mortality due to otomyiasis has not been
reported even with the risk of perforation of the tympanic membrane and
intracerebral migration. Deafness and mastoiditis are reported as the main
myiasis is not part of the classification of otomyiasis but of cavitary
myiasis, and perhaps due to this, its fatality is not reported within
In conclusion, this case report is similar to those
described in other countries. A superficial wound attracts a dipterous female
that deposits its eggs, allowing for the development of early larvae that feed
on healthy tissue. Pain and edema prompt the patient to seek medical attention
where the diagnosis is simple through the visualisation of larvae in the tissue
and larvae extraction. Antibiotics and ivermectin are used for treatment of the
infection and in this case, surgical debridement was performed.As in other
cases, staphylococcal superinfection is reported.The authors declare that there
is no conflict of interest
1 and Figure 2: Multiple Larvae in
3: Tomography without the Mastoid
4: Necrosis of 90% of the Pinna
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Citation: Cardozo A, Espinal MI (2018) Severe Aural Myiasis in Emergency Room. J Trop Med Health JTMH-114. DOI: 10.29011/JTMH-114.000114