What's that on your arm?
Is it a pimple?
Why is it itchy?
Wait.
Did it just move?
Your trip to Central America
three weeks ago might have something
to do with this.
What has gotten under your skin?
And how can you get it out?
Botflies are a parasitic fly located mainly
in Central and South America.
They're best known for their metallic,
robotic appearance.
Female botflies
can't complete their life cycle
unless their larvae are buried
in some animal’s skin.
As they grow,
the larvae consume their host's flesh.
But the only species of botfly
that infests humans
is Dermatobia hominis.
Female botflies can also lay eggs
on mosquitoes or ticks.
When the infested arthropods
bite a human or another mammal,
they deposit larvae from those eggs.
In humans,
a botfly infestation looks like
an irritated, red bump
with a hole in the center.
It's a breathing tube for the larvae.
And sometimes,
you can feel movement within the bump.
This botfly infestation sounds scary,
and if it's not treated,
the infestation can get really bad.
But don't cancel your trip
to the beach just yet.
Instead,
follow these steps to stay safe.
Because many botflies will lay their eggs
on insects, like mosquitoes,
it’s hard to avoid botflies
if you’re in an area where they live.
So use bug spray to keep
flies and mosquitoes away.
And if you're going hiking,
use high-top boots and long sleeves
to prevent tick bites.
If you’re indoors,
close your windows and doors after dark,
and use window screens.
Also, don't let foods or liquids accumulate,
and still use bug spray.
And while you're visiting tropical regions,
remember to iron all your clothing
before dressing.
This is especially important
if your clothes dried outside the house
since the fabric may have eggs stuck in it.
After a female botfly
or other carrier lays eggs,
the larvae will hatch after about a week
and rapidly penetrate your skin.
Some common signs
are wounds forming on your skin
with redness,
slight swelling,
and pus coming from the bite.
You could also feel something
moving around under your skin,
pain,
or intense itching.
Usually, a dermatologist or infectologist
observes the wounds
and diagnoses the botfly infestation.
In 2018,
a Florida woman came back
from her honeymoon in Belize.
Two months later,
she noticed a skin lesion that was itchy
but not painful.
She went to her doctor,
who suspected it was
an infected spider bite
and prescribed antibiotics.
But the antibiotics didn’t help,
so she got a second opinion
at a wound management clinic.
Her wound had a hole in the center
and pus coming out of it.
And the bite felt hard to the touch,
as if there were a bean or an egg inside it.
When the doctors cut open the lesion,
they found an insect with a tapered shape
and rows of spines and hooks.
Pathologists identified it
as a human botfly larva.
The specialist said that if the larva
had not been surgically removed,
it could have matured into an adult fly
and creating a bigger hole in her skin
as it grew.
Within a week of its removal,
her skin had completely healed.
The most common method
of removing a botfly larva
is to apply a topical anesthetic,
slightly enlarge the opening,
and use forceps or tweezers
to remove the larva.
Other methods include
using a venom extractor syringe
to suck out the larvae.
And taking the antiparasitic drug
avermectin,
causes the larvae to suddenly
leave the skin.
Also, flooding the opening with iodine
can make the fly poke out of the hole
so it can be removed with forceps.
Another way to kill the larva
is by suffocating it.
Seal its breathing hole
with something greasy like petroleum jelly.
But if you don't have any,
bacon grease can work just as well.
Then enlarge the hole
and remove the carcass with forceps.
Forcefully squeezing the larvae out
like you’re popping a pimple can work,
but it can also be dangerous and painful.
The larva's spines
can get stuck in your skin,
and rupturing the larva's body
can cause anaphylactic shock.
That makes it harder to remove
all parts of the bug,
increasing your chance of an infection.
Even though a botfly infestation
is not too dangerous on its own,
neglecting an infection can kill you.
So if you visit Central or South America,
be very cautious around damp
and forested areas,
and you should be able to avoid
becoming infested by botflies.
But botflies aren't the only
creepy creatures you should
watch out for.
Something else is waiting
to poke your skin
and drink your blood.
How dangerous can a tick bite be?
Find out here.