The image on the left shows the lesion on the woman’s skin. The human botfly larva (Dermatobia hominis) was able to breathe through the hole in the center. The image on the right shows the larva after it was removed. The rows of black spines make it difficult to extract.
Credit: Mina Shenouda, MD, et al/Journal Investig Med High Case Rep./American Federation for Medical Research/CC by 4.0
A Florida woman will probably never forget her honeymoon in Belize, but not for the usual reasons. Instead, her trip was memorable because of a small souvenir she unknowingly brought back with her: a baby fly growing in her skin.
But it wasn’t until the 36-year-old woman had been back home for two months that she noticed something was amiss.
According to a recent report of her case, it was at this point that she saw what looked like a pimple on the left side of her groin. The skin lesion was itchy, but not painful. So, thinking she may have been bitten by an insect in Belize, the woman went to see her doctor, who suspected it was an infected spider bite and prescribed antibiotics. [27 Oddest Medical Cases]
But the antibiotics didn’t help, according to the case report, published online Oct. 7 in the Journal of Investigative Medicine High Impact Case Report.
That’s when the woman decided to get a second opinion at a wound management clinic.
The lesion looked like a small bite, with a hole in the center and pus coming out of it, said lead case report author Dr. Enrico Camporesi, a specialist in wound healing at Memorial Hospital in Tampa, Florida, who treated the woman.
But there was something unusual about the bite, Camporesi told Live Science: The skin on the wound felt hard to the touch, like there was a bean or egg inside of it. Concerned this could be an infection in the woman’s lymph node, Camporesi asked a surgeon to take a look.
The surgeon, however, suspected something completely different: That the hard bump may be some sort of small creature, under the woman’s skin, Camporesi said.
The surgeon turned out to be right, and when doctors cut open the lesion, they found an insect with a tapered shape and rows of spines and hooks. Pathologists identified the insect as a human botfly larva.
Live baby fly
Fully grown, the human botfly (Dermatobia hominis) resembles a large bumblebee, and is commonly found in Central and South America, according to the University of Florida entomology department. Botfly larvae (the wingless, immature forms of the insects) can burrow into human skin, essentially carving out a haven where they can grow and develop into adults. In medical terms, the infestation is known as “myiasis,” according to the case report. [8 Awful Parasite Infections That Will Make Your Skin Crawl]
Botfly infestations are rarely seen in the U.S., but they are a common skin problem in Central America, Camporesi said. But the infestations aren’t the result of a female botfly laying her eggs on human skin. Rather, the female fly deposits her mature eggs on the body of another insect, such as a mosquito or a fly. Then, when the mosquito or fly bites a person, the mature egg is injected into the person’s skin, where it burrows down beneath the surface and, thanks to the skin’s warmth, hatches into a larva, Camporesi said.
But when a larva burrows into to skin, it needs to leave a hole to breathe through. Indeed, the hole observed on the woman’s lesion was just that — a source of air for the baby fly. (People in Belize may use home remedies, such as placing petroleum jelly, bacon strips, nail polish or plant extracts over the central opening to suffocate the larva, according to the case report. Several hours later, the larva will emerge head first seeking air, and the insect can be extracted with tweezers.)
Camporesi noted that if the larva had not been surgically removed, there’s a chance it could have matured into an adult fly, creating a bigger hole in the skin as it grew larger.
Needless to say, the woman was very upset to learn she’d had a fly growing in her groin after her honeymoon. But within a week of its removal, her skin had completely healed.
Originally published on Live Science.